Android OTP Login & Authentication

@mrresearcher99

Hello, I have 5+ years of experience in Java, Kotlin, Android, and iOS and have built multiple apps using secure SMS-OTP authentication. I can develop a complete Android-only OTP login system that includes: Phone number input & validation OTP generation and SMS sending via a reliable gateway Secure backend verification with expiry & retry limits Resend OTP with cooldown timer Session token creation, storage, and refresh Proposed Stack: Android in Kotlin + lightweight backend (Node.js or PHP/Laravel) Deliverables: Clean, well-documented Android source code Backend / cloud function for OTP send & verify Setup instructions I focus on security, clean architecture, and smooth user experience. Happy to discuss SMS provider, backend preference, timeline, and cost. Best regards, Bhargav

@bitwiz

Hi, I’m an experienced Android developer and I can build a clean, secure SMS-based OTP login flow for your app. I’ve done similar projects before and will use SMS123 as the gateway to ensure reliable OTP delivery. I’ll handle the full cycle—accepting phone numbers, sending and validating OTPs with expiry and limited retries, handling resends, and managing session tokens. You’ll receive fully documented source code, any backend/cloud setup needed, and clear instructions so you can run it smoothly in your environment.

@softwarelinkerrs

With our abundant experience in Android app development and our solid understanding of API development and mobile app architecture, we at SoftwareLinkers are not just skilled in writing code, we're experts in designing solutions that perfectly match your business goals. The project you're presenting aligns perfectly with our expertise and we can guarantee an efficient, secure, and highly functional login & authentication system for your Android-only application. Our proficiency in setting up robust databases using PHP & MySQL together with ensuring scalable and data-driven web applications will ensure that the OTPs dispatched from reliable SMS gateways are handled securely and efficiently. Moreover, our comprehension of RESTful APIs will be essential in the integration of both the front-end and back-end processes for your application. As a team with a high client retention rate and a formidable job success record, ensuring on-time delivery through clear communication remains our top priority at all times. Rest assured, once we've implemented the full authentication cycle, we'll provide you with comprehensive documentations to facilitate easy setup without any guesswork—giving you complete control of your project. I'm eager to discussing the details of your project further!

@Rajoriadares

Hello Client, Greeting of the day!!!! I read your job description. I can do this job with quality product. I am always available for your support. Thanks

@abhishek060

Hi, I can build your hotel booking platform with direct Amadeus, Sabre, and Travelport API integrations, ZIP-based geo search with distance sorting, filtered results, secure IATA validation at checkout, and real-time booking confirmation—fully documented and cloud deployed. Question: do you already have active agency credentials and API access for all three GDS providers, or should I assist with the certification and sandbox-to-production approval process as part of the scope? Can we discuss on chat. Regards Abhishek

@maisamraza1996

Hi, I’m interested in implementing your Android-only SMS OTP authentication flow with a strong focus on security, reliability, and clean user experience. I have 5+ years of Android development experience and have built multiple OTP-based login systems using Kotlin/Java with secure backend validation. I can deliver the complete authentication lifecycle with no email or username dependency. What I’ll deliver: • Phone number input & validation • OTP generation & SMS dispatch via a reliable gateway (Twilio, Firebase, or local provider) • Secure OTP verification with expiry & retry limits • Resend OTP logic with cooldown • Session token creation, storage & refresh • Clean error handling and edge-case coverage Tech stack: • Android Studio + Kotlin or Java • Firebase Auth / Cloud Functions or lightweight REST backend • Secure token handling (JWT / Firebase session) You’ll receive fully documented source code, backend/cloud functions, and clear setup instructions so you can run it locally without guesswork. I’ll clarify SMS provider details early to ensure smooth integration and testing. Ready to start immediately. Best regards, Maisam Raza

@MQamar123

With over seven years of experience in software development, I have amassed a wealth of expertise that is well-suited to fulfill your project requirements. In particular, my extensive knowledge in Java and Software Architecture makes me an ideal candidate for tackling your Android OTP Login & Authentication project. My familiarization with Kotlin will also enable me to deliver the best solution while adhering to your preferred language. I understand the importance of user security and navigating complex login flows, which is why I am confident in my ability to deliver a clean, reliable and secure authentication system for your application. Additionally, I am skilled at integrating external services and APIs for SMS functionalities, which ensures a smooth pairing between your chosen SMS gateway and application. What sets me apart from other candidates is my commitment to exceeding client's expectations. My adaptability to different tech environments allows me to quickly understand new systems and integrate them seamlessly - a crucial aspect for successful collaborations. As an added value, I will provide comprehensive documentation for the source code and offer any backend/cloud function support you may require to ease implementation on your end. I believe this pitch encloses why I am best placed within my capability to deliver incredible outcomes for the job at hand.

@Yupppp

Send me Sandbox Credentials. Let's build Android OTP Login & Authentication app. I am ready to start right now. Let's discuss more over chat.

@buttphool6991

As a veteran in the app development industry with a core focus on Android, I'm confident in my abilities to deliver an impeccable project for you. My extensive experience includes everything you're seeking for this OTP login solution: from front-end development using Kotlin or Java, to back-end handling with Node.js/Express.js, and meticulous database management. Having worked on similar projects before, I understand the importance of security, speed and scalability for such a system. Additionally, my proficiency with different SMS gateways will ensure we choose the most reliable option that perfectly integrates with your app. My adeptness at architecting robust systems will be instrumental in delivering an ergonomic and secure authentication cycle that guarantees timely dispatch and verification of one-time passwords whilst managing appropriate expiry and retry limits. Furthermore, my commitment to detailed documentation ensures smooth setup and maintenance. I'll provide clear instructions along with the source code and any backend components needed for seamless integration. Committing to your deadline and budget is a trait I hold dear; let's eliminate guesswork from your project by partnering together - impactful code plus effective communication awaits!

@aman720gupta

Here’s your Freelancer-ready bid under 1400 characters, secure and implementation-focused: I can implement a clean, secure, SMS-based OTP authentication flow for your Android app with production-grade reliability. I’ve built phone-number–only auth systems before and understand the importance of rate limiting, expiry logic, and token security. Proposed Stack: • Kotlin + MVVM • Secure backend (Node.js/Firebase Functions) • Reliable SMS gateway (Twilio / MSG91 / regional provider as needed) • JWT-based session handling Flow Implementation: • Phone number validation (E.164 format) • OTP generation server-side (time-bound + hashed storage) • Limited retry attempts + rate limiting • Resend logic with cooldown timer • Verification endpoint issuing secure session token • Token refresh mechanism • Encrypted local storage (EncryptedSharedPreferences) Security Focus: • No OTP logic exposed client-side • Expiry enforcement on server • Brute-force protection • HTTPS-only communication Deliverables: • Fully documented Android source code • Backend/cloud function code • Setup guide (SMS provider keys, env variables, deployment steps) • Clean architecture for future auth extensions Everything will be structured so you can run it locally or deploy easily. Happy to discuss SMS provider choice early to ensure smooth integration.

@dineshk743

Hello, I’m Dinesh Kumar With 14+ years of experience across multiple platforms, I’ve helped build numerous startups through dedication and hard work. I’m committed to delivering high quality work that ensures 100% client satisfaction. Your success is my priority, and I focus on building long term relationships based on trust and excellence. Expertise: Web & App Development – React.js, Node.js, JavaScript, PHP, MySQL, WordPress, Magento, CodeIgniter, Shopify, .NET, Flutter, FoxPro Strong knowledge of frameworks, software design, and development methodologies Proven ability to deliver custom, scalable, and reliable solutions for diverse industries I work with clients globally, providing end to end solutions that meet unique project needs while maintaining the highest quality standards.

@tamannarajput18

With a comprehensive experience of 6+ years in Full Stack Android Development, I'm the ideal candidate to build your SMS-based login and authentication system. As your go-to developer, not only will I provide you with a clean, secure, and reliable login flow but also ensure the entire process is smooth sailing for even new users. I am well-versed in Kotlin and Java - allowing me to choose the best-suited language for this project. My understanding of backend systems and cloud integration along with my proficiency in wiring up a full authentication cycle makes me confident that I'll be able to deliver the desired functionality effectively. I have worked extensively with SMS gateways and their integration - which means that not only can I wire this process end-to-end but troubleshoot any issues too. Moreover, my track record of successful client deliveries and versatile skills extend beyond just android development; ranging from AI Chatbots to optimizing SEO performance – assuring you a support system even after the project’s completion. Looking forward to bringing your vision to life with a practical yet innovative solution!

@Hemantt841

With 7 years of experience in mobile app development, I am the best fit to complete this Android OTP Login & Authentication project. I have the relevant skills to deliver a clean and secure login flow that relies on SMS OTP verification. How I will complete this project: - Implement a user-friendly interface for entering the phone number and receiving the OTP - Integrate a reliable SMS gateway for OTP dispatch - Develop logic for OTP validation with expiry and retry limits - Implement resend functionality for OTP - Manage session tokens for verified users Tech stack I will use: - Android Studio - Kotlin or Java - Firebase Cloud Messaging for SMS dispatch - Firebase Authentication for user verification - Firebase Cloud Functions for backend logic I have worked on similar solutions in the past, ensuring a seamless authentication process for users. The deliverables will include well-documented source code, necessary backend or cloud functions, and setup instructions for easy deployment in your environment. For any queries regarding the SMS provider or sandbox credentials, feel free to reach out early in the project timeline to ensure smooth integration. Let's work together to create a robust and efficient OTP login system for your Android application.

@techwagger

As someone with over a decade of experience in mobile app development and software architecture, I can assure you that choosing me for your Android OTP Login and Authentication project would provide your users with a secure and seamless experience. My proficiency in Java, Kotlin, and Android app development has been honed by the successful delivery of multiple projects. Handling the complete authentication cycle, from accepting phone numbers to validating OTPs, falls within my comfort zone. I have an informed understanding of various SMS gateway options, ensuring that we select a reliable one best suited for your app's needs. Furthermore, as a seasoned Application Solution Architect, I'm skilled at designing scalable solutions that fit specific needs — your project will be no exception. To streamline the verification process, I can incorporate sensible expiry and limited retries for stored refreshment of session tokens once the user is verified. My work doesn't stop at just writing code; I guarantee the delivery of documented source codes as well as any needed backend or cloud function required for sending and verifying OTPs. Rest assured, my instructions will be concise and useful enough to let you run the system effortlessly on your own. Let's maximize your business potential together!

@codnexa

As an accomplished Android App Developer, with a keen focus on secure login and authentication systems, I am well-poised to undertake your project. Since your app requires precise SMS-based OTP verification, my extensive knowledge of both Kotlin and Java will ensure an optimized user flow for your application. Given the sensitive nature of handling login credentials without the need for usernames or emails, I am fully aware of the importance of selecting a reliable SMS gateway provider to ensure SMS delivery. My experience in utilizing backend/cloud functions to send and verify OTPs add significant value to this project. Your project's success relies on maintaining secure and efficient login cycles with session management and token refreshment. Having successfully implemented similar features in diverse Android apps, I'm confident in my ability to deliver excellent results for all the deliverables outlined. Let's optimize your app's security together!

@abdullahsaeeddev

Hi, I can build a secure, production-ready SMS OTP login flow for your Android app using Kotlin, complete with backend verification and proper session handling. I’ll integrate a reliable SMS gateway, implement expiry + retry limits, secure token management, and clean resend logic. You’ll receive well-documented source code, backend/cloud setup, and clear deployment instructions so everything runs smoothly in your environment. Ready to start immediately.

@arbaji1

I’m a React Native developer building high-performance cross-platform mobile applications for Android and iOS. I specialize in creating scalable, production-ready apps with clean UI, smooth performance, and robust backend integration.

@shashikiot12

Hello Hope you're doing well I fully understand your requirements and am ready to build a secure, clean Android OTP login system. With strong experience in Android (Kotlin/Java), I will deliver a fully functional, fast-loading app that matches your needs. I will ensure: Phone number input & OTP dispatch via a reliable SMS gateway Secure OTP validation with expiry, limited retries, and resend logic Session token handling after verification Clean, maintainable code with backend/cloud setup Full documentation and setup instructions Full support and responsibility, including fixing any minor errors after delivery I’m ready to start immediately and will deliver a robust, fast, and fully functional OTP login flow for your app. Let’s discuss the project further here in the chat. Thanks & Regards Shashi Kant Singh

@sivag47

Hello, I can implement a secure SMS-based OTP login flow for your Android application, covering the complete authentication cycle from OTP generation to session handling. I have 5+ years of experience building secure backend services and mobile-integrated authentication systems, ensuring reliable login flows with proper validation and security controls. Solution includes: • Phone number-based login without usernames or emails • OTP generation and dispatch via a reliable SMS gateway • Secure OTP verification with expiration and retry limits • Resend OTP handling • Session token creation after verification • Backend service/API for OTP send and validation • Clean Android implementation in Java • Documented source code and deployment/setup instructions The system will be scalable, secure, and easy to maintain, allowing future extension for additional authentication features if required. I would be glad to discuss gateway selection and integration details to ensure smooth implementation. Best regards, Siva Kumar Gadesina