🔑Best Check-In Services

Google's Firebase is an entire app development platform that's packed with features.It comes with storage, cloud functions, monitoring and, of course, user authentication. The free tier comes with 50,000 MAUs. Beyond that pricing start at $0.0055/MAU and goes down to as low as $0.0025/MAU as you scale to millions of users. Firebase authentication supports email and password auth, phone auth, magic links, two-factor authentication and social identity providers - mainly Google, Google Play Games, Facebook, Apple, Microsoft, Twitter, GitHub and OAuth access tokens.

Clerk is a comprehensive user management and authentication platform designed to streamline how developers handle user accounts within web and mobile applications. It offers a suite of embeddable UI components—such as <SignIn/>, <SignUp/>, <UserButton/>, and <UserProfile/>—that integrate seamlessly into your application without redirecting users off-site. These components are fully customizable to match your brand, making the user experience cohesive and frictionless. Under the hood, Clerk provides a robust API and SDKs compatible with modern frameworks like Next.js, Remix, React, and Expo. It handles the entire authentication lifecycle, supporting multifactor authentication (MFA), session management, passwordless sign-in (via magic links or one-time passcodes), and traditional password-based methods with breach detection. The platform also integrates social sign-on (SSO) with over 20 providers, enabling quick user onboarding while adhering to security best practices. Clerk’s security posture includes SOC 2 Type 2 certification and CCPA compliance, with continuous third-party audits and penetration testing. Fraud prevention measures, like disposable email blocking and bot detection powered by machine learning, are built-in to reduce spam and abusive sign-ups. For B2B SaaS applications, Clerk provides advanced multi-tenancy features, enabling organization-based user management with custom roles, permissions, auto-join functionality based on email domains, and invitation systems—all accessible through both code and an admin dashboard. Developers benefit from rapid integration, significantly reducing the time spent on building authentication systems from scratch. Clerk acts as the single source of truth for user data and integrates seamlessly with popular backend services like Supabase, Firebase, and Convex. With free access for up to 10,000 monthly active users, it’s positioned as a scalable solution that grows with your application’s needs.

Auth0 is an identity and access management (IAM) platform designed to simplify authentication and authorization for applications. It provides a flexible solution that allows developers to implement secure login systems without having to build them from the ground up. Auth0 supports various authentication methods, including username-password credentials, social logins (like Google, Facebook, and GitHub), enterprise identity providers (such as Active Directory and SAML-based systems), and passwordless options. The platform is highly adaptable, offering over 30 software development kits (SDKs) that cater to a wide range of languages and frameworks—JavaScript, Python, .NET, iOS, Android, and more. This makes integration straightforward regardless of the tech stack. Beyond basic authentication, Auth0 offers advanced features like multi-factor authentication (MFA), single sign-on (SSO), and fine-grained authorization. These tools enable organizations to enforce complex access control policies, supporting both role-based (RBAC) and attribute-based (ABAC) models. Auth0 also addresses enterprise needs through features like user provisioning, directory synchronization, and support for B2B, B2C, and B2E use cases. It’s designed with scalability in mind, making it suitable for both startups and large enterprises. The platform’s extensibility allows developers to customize authentication flows, implement rules for conditional access, and integrate third-party services. Since its acquisition by Okta, Auth0 operates as a product unit under the Okta umbrella, complementing Okta’s broader suite of identity solutions while maintaining a developer-first focus. This combination brings together Okta’s enterprise-grade security with Auth0’s developer-centric approach, offering a comprehensive solution for modern identity challenges.

Supabase is the open-source alternative to Firebase. Like Firebase, it's a complete app development platform with user authentication, cloud functions, APIs, Postgres database, storage, vector embeddings, and other features. Supabase projects come with PostgreSQL's policy engine for fine-grained user access rules. It has social login integrations with Google, Facebook, GitHub, Azure (Microsoft), Gitlab, Twitter, Discord, and many more. They offer a customizable authentication component for React. Phone login and MFA can be added through third-party SMS providers such as Twilio or Bird. The free tier comes with 50,000 monthly active users. The Pro plan, at $25/month, comes with 100,000 MAUs and $0.00325/MAU beyond that.

Authentication made simple, secure, and scalable for your apps. Authsmith removes the pain of building secure authentication from scratch. In modern apps, auth is foundational but complex—difficult to implement securely, time-consuming to integrate across platforms, and easy to misconfigure. Authsmith provides a secure, drop-in solution that lets teams move fast without compromising safety.

The biggest advantage of Cognito is that it's a part of the AWS ecosystem and integrates well with other AWS services. The free tier comes with 50,000 MAUs and the price for each additional MAU starts at $0.0055/month and goes down to as low as $0.0025/month as you scale to tens of millions of users. It integrated with four federated identity providers - your users can sign up with Facebook, Google, Apple and Amazon.

My personal favorite! Specializes in cruise bookings and offers a price guarantee. Features deals, discounts, and last-minute offers.

Owlbot offers a cutting-edge AI-powered chatbot service that seamlessly integrates with your data to provide instant responses for you, your customers, or your team. Deploying a tailor-made AI chatbot with Owlbot is straightforward, enhancing both customer service and the efficiency of data analysis with minimal effort. Our AI chatbot is capable of handling 90% of inquiries from customers, clients, or employees effortlessly (>90 languages supported). It can import data from a variety of sources, including documents, markdown files, and webpages, ensuring that you receive precise, immediate answers. Additionally, you can connect the chatbot to your internal tools to access private data in real-time and provide timely responses. You can choose from 12 different large language models (LLMs), such as Mistral, OpenAI, and Anthropic, to find the option that best fits your needs. Owlbot also captures the details of interested visitors, helping you compile a list of potential leads and expand your business opportunities.

Endura is the first comprehensive digital estate planning platform specifically designed to assist individuals and families in securely managing, storing, and distributing their digital assets. In an era where our lives are increasingly tied to the digital world, Endura offers a sophisticated and modern solution for managing online accounts, documents, and electronic assets. This platform ensures that these important digital possessions are handled according to an individual's specific wishes after their passing, providing peace of mind and security. An individual can upload their digital assets, assign beneficiaries to those assets, and invite executors to carry out their wishes on the platform. Whether you're organizing your personal digital life or offering professional estate planning services, Endura empowers you to manage and protect digital legacies effectively. This makes it an essential tool in the modern age, where digital assets are as important as physical ones.

Breathworx is an on-demand breathwork service designed for stress relief, decision clarity, and a happier mood, with guaranteed results in a single session—even for those who “can’t meditate.” Folks who’ve tried it say they: Feel less “in their head” generally Feel an overwhelming sense of gratitude and clarity Feel more confident, calm, & authentic in social situations Get clearer answers in big decision making Relieve stress, anxiety, heartbreak, loss, and depression Have more reliable stress coping mechanisms Release the “emotional gunk” that builds in them Feel more grounded and in touch with their bodies Are less reactive in difficult situations The classes primarily use guided meditations and Circular Breathwork, a simple technique involving 2 breaths in (belly, then chest) and 1 breath out, all through the mouth. Also known as 2-part breathwork, holotropic breathwork, or triangle breathing, this method yields transformative results in a short amount of time. Breathworx offers both full-length 40-60 minute sessions and shorter 10-20 minute versions, accessible on any browser or device, anytime. Whether you use this "cheat code" once a week, once a month, or daily during particularly hard times, it's all up to you. Many people find that even a single class is worth more than years of therapy, where one session can cost more than a yearly Breathworx membership. In fact, if you take just one full class a year, you’ll likely value the benefits beyond the yearly subscription price. Most in-person classes have about 30 minutes of breathing wrapped in some meditation or gratitude practice, making for about 45 minutes total. Breathworx offers similar formats, as well as shorter versions, ensuring there's a session that fits your schedule and needs. Whether you're looking to relieve stress, gain clarity, or simply add a powerful tool to your wellness toolkit, Breathworx is designed to be as transformational, enjoyable, and meaningful as possible.

Clerk is a comprehensive user management and authentication platform designed to streamline how developers handle user accounts within web and mobile applications. It offers a suite of embeddable UI components—such as <SignIn/>, <SignUp/>, <UserButton/>, and <UserProfile/>—that integrate seamlessly into your application without redirecting users off-site. These components are fully customizable to match your brand, making the user experience cohesive and frictionless. Under the hood, Clerk provides a robust API and SDKs compatible with modern frameworks like Next.js, Remix, React, and Expo. It handles the entire authentication lifecycle, supporting multifactor authentication (MFA), session management, passwordless sign-in (via magic links or one-time passcodes), and traditional password-based methods with breach detection. The platform also integrates social sign-on (SSO) with over 20 providers, enabling quick user onboarding while adhering to security best practices. Clerk’s security posture includes SOC 2 Type 2 certification and CCPA compliance, with continuous third-party audits and penetration testing. Fraud prevention measures, like disposable email blocking and bot detection powered by machine learning, are built-in to reduce spam and abusive sign-ups. For B2B SaaS applications, Clerk provides advanced multi-tenancy features, enabling organization-based user management with custom roles, permissions, auto-join functionality based on email domains, and invitation systems—all accessible through both code and an admin dashboard. Developers benefit from rapid integration, significantly reducing the time spent on building authentication systems from scratch. Clerk acts as the single source of truth for user data and integrates seamlessly with popular backend services like Supabase, Firebase, and Convex. With free access for up to 10,000 monthly active users, it’s positioned as a scalable solution that grows with your application’s needs.

Stytch provides a suite of tools designed to simplify authentication, authorization, and security for web and mobile applications. If you're developing an app and need a way for users to log in—whether with passwords, passkeys, or entirely passwordless methods—Stytch offers APIs and SDKs that handle these complexities. Their focus is on making authentication seamless for both developers and end-users while ensuring high security standards. For businesses, particularly B2B SaaS companies, Stytch enables advanced features like multi-tenancy, role-based access control (RBAC), and single sign-on (SSO). They provide an embeddable admin portal, allowing enterprise customers to manage their own authentication configurations, organizational settings, and integrations with identity providers—without constant developer involvement. Stytch places a strong emphasis on scalability and flexibility. Their tools are designed to “just work” across a range of use cases, from simple consumer apps to complex enterprise platforms. Developers can choose how much of the authentication flow they want to control—using pre-built UI components for quick implementation or leveraging headless SDKs and backend APIs for a fully customized experience. Security and fraud prevention are also core to Stytch’s offering. They provide real-time bot detection, device-aware multi-factor authentication, and intelligent rate limiting to protect against credential stuffing and other forms of account abuse. Their infrastructure ensures that login codes and authentication requests are delivered reliably, even when SMS or email providers fail. Stytch supports a broad range of programming languages and frameworks, including Python, Node.js, Java, React, and iOS, making integration into existing tech stacks straightforward. Their platform is designed for developers who want to build secure, user-friendly authentication systems without reinventing the wheel.

Amazon Cognito is an identity platform for web and mobile apps. It’s a user directory, an authentication server, and an authorization service for OAuth 2.0 access tokens and AWS credentials. With Amazon Cognito, you can authenticate and authorize users from the built-in user directory, from your enterprise directory, and from consumer identity providers like Google and Facebook.

The biggest advantage of Cognito is that it's a part of the AWS ecosystem and integrates well with other AWS services. The free tier comes with 50,000 MAUs and the price for each additional MAU starts at $0.0055/month and goes down to as low as $0.0025/month as you scale to tens of millions of users. It integrated with four federated identity providers - your users can sign up with Facebook, Google, Apple and Amazon.

My flight from Bangkok to Los Angeles was completely packed and the seats were tiny. This is arguably not the airline's fault but the layover in Manila was one of the worst I've had. You are herded from one queue to another for hours, surrounded by a crowd of people at all times.

My personal favorite! Specializes in cruise bookings and offers a price guarantee. Features deals, discounts, and last-minute offers.

because fuck you that's why

Trefundo is an AI-powered platform that takes the stress out of dealing with non-refundable hotel bookings. Travelers often face unexpected changes—plans get canceled, schedules shift, or emergencies arise—only to discover that their hotel reservations can’t be refunded. Trefundo is designed to solve exactly this problem. Using advanced automation and AI negotiation strategies, Trefundo works on your behalf to recover money from bookings that are typically considered “lost.” Whether through refund requests, policy loopholes, resale opportunities, or consumer protection laws, the platform explores every possible option to maximize your chances of saving money.

Track.Cruises is revolutionizing how travelers find and book cruise vacations by providing intelligent price tracking, real-time alerts, and data-driven insights across multiple cruise lines and markets. What We Do: Track.Cruises monitors thousands of cruise itineraries from major cruise lines including Costa Cruises, Royal Caribbean, and Norwegian Cruise Line across 6 regional markets (US, UK, Germany, Austria, Australia, Italy) and coming more. Our platform automatically tracks price fluctuations and sends instant notifications when your dream cruise drops in price. Key Features: - Real-Time Price Alerts: Get notified immediately when prices drop on cruises you're tracking - AI-Powered Predictions: Machine learning algorithms analyze historical data to predict optimal booking times - Multi-Market Comparison: Compare prices across 6 regional markets in 4 currencies to find the best deals - Price History Charts: Visualize pricing trends with up to 1-year historical data - Recent Price Drops Dashboard: Browse the hottest deals from the last 5 days with color-coded savings badges - Cabin Pricing Transparency: See pricing across all cabin types (Interior, Oceanview, Balcony, Suite) - Favorites & Custom Alerts: Set target prices and get notified when they're reached Why Choose Track.Cruises: Unlike traditional booking sites that profit from commissions and show biased results, Track.Cruises is a neutral platform focused on helping travelers save money. Our users save an average of $350 per booking by leveraging our real-time tracking and intelligent alerts. Perfect For: - Price-conscious travelers who want the best cruise deals - Established cruisers planning their next adventure 6-12 months in advance - Millennial explorers seeking budget-friendly cruise experiences - Families coordinating multi-generational cruise vacations The Problem We Solve: Cruise prices fluctuate constantly, making it nearly impossible to know if you're getting a good deal. Traditional cruise booking sites prioritize their commissions over your savings, and manually checking prices across multiple sites and markets is time-consuming and frustrating. Our Solution: Track.Cruises automates the entire process, monitoring thousands of cruises 24/7 and alerting you instantly when prices drop. With our AI predictions, you'll know exactly when to book for maximum savings. Join thousands of smart travelers who never overpay for cruises. Start tracking your dream vacation today at track.cruises

Amazon Cognito is an identity platform for web and mobile apps. It’s a user directory, an authentication server, and an authorization service for OAuth 2.0 access tokens and AWS credentials. With Amazon Cognito, you can authenticate and authorize users from the built-in user directory, from your enterprise directory, and from consumer identity providers like Google and Facebook.

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Our VPN service is without limitation in traffic, bandwidth or time. Just install and connect – No Registration or Personal Data required. - Unlimited Fast Servers - High-speed Connection - No Logs - No Registration No Registration or Personal Data is Required to Connect Strict no log policy, user data is not passed on to third parties. No logging or collection of personal information.

I've been building a file conversion platform that handles PDFs, videos, audio, images, and QR codes. Extract text, merge files, add signatures, convert formats and all that jazz. To monetize it, I added monetized APIs so you can integrate these tools into your workflows. You can: Extract text from PDFs instantly Merge multiple PDFs into one Split large PDFs into smaller files Add digital signatures Apply watermarks for branding Compress PDFs to save storage Convert HTML to PDF Convert videos, audio, and images Generate QR codes Process everything via API Built with: Next.js 15, React, TypeScript, Flask, Python, Supabase, Tailwind CSS, Framer Motion, PyMuPDF, NextAuth, Resend, PayFast Free to start. Pay as you scale. Get started: trevnoctilla.com

Allscreenshots started with a simple frustration: existing screenshot APIs were either overpriced, overcomplicated, or missing features developers actually need. To fix this, we're building the screenshot service we wished existed when we needed one. A service which respects both your budget and your time, with great support whenever you need it. No surprise bills from runaway usage, and just a clean, well-documented API that does exactly what it promises. What makes us different? We went beyond single captures. Our compose endpoint lets you combine multiple screenshots into comparison views, grids, and layouts, thus eliminating the work required by teams so they can focus on more rewarding features. We're building this in public, documenting the real decisions, trade-offs, and challenges along the way. Because we believe the best tools come from developers who've felt the same pain points you have, and allowing you to provide input in the direction we're taking, so we can best address the challenges you face! We offer simple, affordable pricing, easy documentation, and great support. Plus, screenshots that just work.

KentekenGids is a premier Dutch online platform for comprehensive vehicle information. This user-friendly website offers a range of services centered around vehicle data: - Extensive Database: Users can access detailed information on more than 15 million vehicles registered in the Netherlands by simply entering a license plate number. - Multi-Source Reports: The platform aggregates data from authoritative sources including the RDW (Dutch Road Transport Agency), NAP (National Auto Pass), and APK (Dutch MOT equivalent) to provide thorough vehicle histories. - Security Checks: Visitors can quickly verify if a vehicle has been reported stolen, enhancing security for potential buyers. - Odometer Fraud Prevention: The site allows users to review a vehicle's recorded mileage history, helping to identify potential discrepancies. - Insurance Insights: KentekenGids provides valuable information about a vehicle's insurance status and history. By offering both complimentary and premium license plate checks, KentekenGids empowers consumers and businesses to make well-informed decisions in various automotive transactions, from purchases and sales to insurance considerations. The platform's ultimate goal is to increase transparency in the Dutch automotive market.