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We run Tred, a secure cloud storage platform. We need production-ready apps for Android, iOS, and Windows that deliver a polished, Google-Drive/Dropbox-level experience: Selective folder backup & auto-sync Reliable uploads/downloads with resume Background sync and scheduling Built-in preview (images, video, PDF, text) Sharing via secure links Windows app with a real, mountable virtual drive (appears as a drive letter in Explorer) This is not a basic uploader. We want a clean UX, efficient sync engine, and robust error handling. Scope (all platforms) Auth (token/OAuth against our API) Two-way sync (device ↔ cloud), conflict handling, retry & backoff Selective folders, storage usage, offline files Transfer queue with progress, pause/resume, bandwidth cap Settings: Wi-Fi-only, battery/roaming guards, schedule (realtime/hourly/daily) Theming/branding (dark blue), app icons & store assets Mobile specifics Android & iOS Auto-backup of photos/videos (camera roll + any chosen folders) Built-in video player (stream without full download) Push notifications (completed uploads / errors) > Note: iOS full-device VPN-style behavior is not required; app-scoped sync is enough. (If you can also handle iOS Network Extension in the future, note it.) Windows desktop Virtual Drive: mount Tred as a real drive (read/write, drag-and-drop) Background service for continuous sync Tray app: status, recent activity, quick actions First-run wizard (pick folders, schedule, bandwidth) Tech preferences Mobile: Flutter (preferred) or React Native; native OK if justified Windows: C#/.NET + filesystem driver or Dokany/WinFsp (or equivalent) for the virtual drive Efficient delta uploads (chunked), parallelism, and low CPU/battery use Clean architecture, documented code API We’ll provide endpoints for: Auth, file list, upload (chunked), download, share links Metadata (size, mtime, hash), storage quota Webhooks/events (optional) If you have a proven sync/drive architecture, propose it. If not, implement a standard chunked + hash-verified approach. Deliverables Android APK/AAB (Play-ready), iOS build (App Store-ready), Windows installer + auto-update Full source code + build scripts Config for staging/prod (API base URL, keys) README + short admin guide 30-day bug-fix warranty after delivery Acceptance criteria Stable two-way sync with selective folders Resume after network loss, no data corruption Windows drive mounts reliably and survives reboots Smooth video playback from cloud Passes review on low/mid-range devices (battery/network usage reasonable) Budget & timeline Budget: up to €1,200 (fixed price) Timeline: propose realistic phases; priority Android → iOS → Windows We’re OK with milestones tied to working builds: 1. Android MVP (auth + selective backup + queue) – 30% 2. Android full (video preview + schedule + settings) – 20% 3. iOS parity build – 25% 4. Windows drive + installer – 25% What to include in your bid 2–3 relevant apps you’ve built (sync, cloud, or virtual drive) Brief plan: tech stack, libraries (e.g., Dokany/WinFsp), how you’ll handle conflicts & resume Estimated timeline by milestone Team size and who codes what Nice to have End-to-end encryption option (file-key on device) Delta sync for images/videos (if feasible) Crash/telemetry integration (Sentry, etc.) Basic CI/CD setup
Project ID: 39692176
70 proposals
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Active 9 mos ago
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70 freelancers are bidding on average €1,221 EUR for this job

Hi there, I reviewed and understood your detailed requirements for building production-ready apps for Tred, your secure cloud storage platform. I am an experienced developer specializing in cross-platform app development and efficient sync engine implementation. I can deliver polished Android, iOS, and Windows applications that offer seamless selective folder backup, reliable two-way sync with conflict handling, built-in media previews, and a mountable virtual drive on Windows with robust error handling and smooth user experience. My approach involves using Flutter for mobile apps to ensure performance and battery efficiency, combined with C#/.NET and Dokany/WinFsp for the Windows virtual drive. I focus on building a scalable, secure sync engine with chunked uploads, hash verification, and conflict resolution. I prioritize clean architecture, thorough testing on mid-range devices, and delivering well-documented, maintainable code. I will implement features like background sync, push notifications, bandwidth controls, and a user-friendly interface aligned with your branding. Thanks, Rahul A.
€1,350 EUR in 40 days
7.7
7.7

Hello, I understand that you want to build three polished cloud storage apps for Android, iOS, and Windows, focusing on features like selective folder backup, auto-sync, and reliable uploads. My approach will prioritize a clean user experience, efficient sync, and robust error handling, ensuring your platform stands out against competitors like Google Drive and Dropbox. I propose using Flutter for mobile app development, as it offers a unified codebase and ease of maintenance, while utilizing C#/.NET for the Windows virtual drive implementation. For the timeline, I suggest breaking it down into realistic phases: starting with the Android MVP, followed by full Android features, then developing the iOS build, and concluding with the Windows drive setup. Each milestone will be tied to working builds to keep the project on track. What specific features do you prioritize in the sync engine, and are there any existing apps you can reference for user experience inspiration? Thanks, Shamshad
€1,500 EUR in 28 days
7.0
7.0

Hello, As a seasoned developer, I believe I can create robust and user-friendly cross-platform cloud storage apps for Tred that will exceed your expectations. My deep understanding and hands-on experience with Android, iOS, and C#/.NET make me well-suited for the task. I have developed several sync and cloud-based applications in the past which involved reliable uploads/downloads, selective folder backup, scheduling, and more. To handle your requirements effectively, I propose adopting Flutter (which aligns with your preferences) but I can also work fluidly with React Native or native if necessary. My familiarity with Dokany/WinFsp qualifies me to efficiently build the Windows virtual drive component as well. Moreover, my expertise in chunked uploads/downloads to ensure optimum bandwidth utilization while minimizing CPU/battery usage makes me apt for this project. I understand you value detail-oriented work within your defined budget and timeline. To meet these objectives, I will manage milestones that correspond to working builds which offer progress verifiability along the way. My proposed schedule would have priority set on Android MVP development, followed by progressively enhancing it towards delivering an iOS parity build, culminating with implementing Windows drive functionality in line with your expectation. Your satisfaction is guaranteed; I'll include a 30-day bug-fix warranty after delivery to ensure everything runs smoo Thanks!
€800 EUR in 1 day
6.3
6.3

This is exactly the kind of work I love doing. I specialize in creating robust, user-friendly apps with a strong emphasis on secure cloud storage solutions. I have extensive experience using Flutter for mobile development and C#/.NET for Windows applications, ensuring a seamless and efficient sync engine. I've successfully completed similar projects with a focus on clean UI and reliable performance. I look forward to delivering a polished solution for Tred. I’m happy to offer insight even if you don’t go with me. Regards, Anne S.
€1,050 EUR in 5 days
5.6
5.6

Hello. In a past project, we faced challenges with reliable file syncing across devices due to network interruptions, but we tackled it with robust retry and backoff strategies. I understand you need a polished experience for Tred, focusing on selective folder sync, auto-backup, and conflict resolution. Our plan includes using Flutter for mobile apps and C#/.NET for the Windows virtual drive, ensuring clean architecture and efficient delta uploads. We can deliver an Android MVP in 4 weeks, followed by the iOS build and Windows drive, all while keeping you updated at each milestone. Our team has successfully built similar apps, and we're ready to bring Tred to life with top-notch functionality and design.
€1,125 EUR in 7 days
5.3
5.3

Hey, i will use flutter to create android and ios apps featuring selective folder backup, two-way sync with chunked uploads/downloads, conflict resolution, retry with backoff, and pause/resume support, including a built-in video player for streaming and push notifications for upload status. authentication will use token or oauth against your api. for windows, i will use c# with dotnet and dokany or winfsp to provide a virtual drive that mounts as a drive letter, supporting read/write and drag-and-drop, with a background sync service, tray app for status and quick actions, and a first-run wizard for folder selection and scheduling. sync will use hash-verified chunked transfers with delta updates to reduce bandwidth and handle network interruptions smoothly. apps will include scheduling, bandwidth limits, and wifi/battery/roaming guards, with a dark blue theme and appropriate icons. code will be clean, modular, documented, and tested on mid-range devices to ensure efficient cpu and battery usage. Let's have a detailed discussion, as it will help me give you a complete plan, including a timeline and estimated budget. I will share my portfolio in chat I look forward to hear from you. thanks Regards, Mughira
€1,125 EUR in 7 days
4.9
4.9

Hello Pedro Maria A., I have read the project details and understood the overall requirement. I am Abdul, with 5 years of experience in Mobile App Development, specializing in Android, iOS, and Windows platforms. I have successfully delivered multiple projects in the same domain. For the Cross-Platform Cloud Storage Apps project for Tred, I plan to utilize Flutter for mobile development and C#/.NET for the Windows app, ensuring efficient sync, clean UX, and robust error handling. My portfolio can be viewed https://www.freelancer.com/u/mannanmaan1425 Please ping me back so we can discuss the project further in the chat. Best regards, Abdul
€750 EUR in 4 days
4.3
4.3

Hey, i will use flutter for android and ios apps to create selective folder backup, two-way sync with chunked uploads/downloads, pause/resume, conflict detection, and retry logic, integrating push notifications and a built-in video player for smooth streaming; for windows, i will use c# with dotnet and dokany to create a virtual drive that mounts in explorer with full read/write support, plus a background sync service and tray app for quick access and status; the backend api endpoints for auth, file list, upload/download, sharing, and metadata will be integrated with secure token or oauth authentication; sync will include delta uploads using hash verification for data integrity, with scheduling and bandwidth control settings to optimize battery and network use; all code will be modular and documented, with staged deliveries starting from android mvp through ios parity and finishing with the windows app, including build scripts and admin guides. Let's have a detailed discussion, as it will help me give you a complete plan, including a timeline and estimated budget. I will share my portfolio in chat I look forward to hear from you. thanks Regards, Ahmad
€1,125 EUR in 7 days
4.4
4.4

Hello Pedro, I am Roman Golovin, a seasoned Mobile App Developer with over 7 years of experience in Android, C# Programming, and Mobile App Development. I have carefully reviewed your project requirements for developing cross-platform cloud storage apps for Tred. My expertise spans front-end, back-end technologies, and cloud platforms, including JavaScript (React, Angular, or Vue.js), Node.js, Python, AWS, Azure, PostgreSQL, and MongoDB. I specialize in building scalable, high-performance applications and implementing best coding practices. I am excited about the opportunity to contribute my skills to this challenging project. Let's discuss further details in the chat. Regards, Roman Golovin
€1,200 EUR in 7 days
3.4
3.4

Hello Pedro Maria A., I hope this message finds you well. My name is Mikhail, and I'm reaching out to express my interest in your project titled "Cross-Platform Cloud Storage Apps for Tred (Android, iOS & Windows) — Auto Sync, Selective Folders, Virtual Drive" With extensive experience and a strong skill set in iPhone, Mobile App Development, Windows Mobile, Android and C# Programming, I am confident in my ability to deliver outstanding results that meet your expectations. I have a proven track record of successfully completing similar projects, and I am eager to bring my expertise to your initiative. Understanding the importance of timely delivery and budget constraints, I am committed to providing efficient solutions without compromising on quality. I prioritize clear communication and collaboration, ensuring that we are aligned throughout the project's duration. I would be thrilled to discuss how I can contribute to your project's success in more detail over chat. Looking forward to the opportunity to work together. Best regards, Mikhail
€1,000 EUR in 12 days
3.1
3.1

Hello, client I'm Denis Redzepovic, an experienced developer skilled in iPhone, Android, Mobile App Development, C# Programming and Windows Mobile. I specialize in building high-performance, scalable, and visually appealing applications that deliver smooth functionality and a seamless user experience. Whether you need full app development, UI/UX improvements, API integrations, or performance optimizations, I can provide a tailored solution that fits your needs. I focus on clean, maintainable code with responsive UI, smooth animations, robust state management, and seamless API integration. My approach ensures scalable architecture and pixel-perfect design, delivering consistent performance across Android and iOS platforms. With cross-platform efficiency and attention to detail, I’m confident I can add strong value to your project. I’d love to discuss your requirements and find the best approach to bring your vision to life. Thanks, Denis
€750 EUR in 12 days
3.1
3.1

Hello Pedro, I can develop cross-platform cloud storage apps for Tred, ensuring a polished user experience across Android, iOS, and Windows. Utilizing Flutter for mobile and C#/.NET for Windows, I will implement selective folder backup, auto-sync, and a virtual drive that meets your requirements. Thanks, Hardik
€1,500 EUR in 15 days
2.0
2.0

Hello Tred team, I'm excited to work on your Cross-Platform Cloud Storage Apps project! I propose a detailed plan with a focus on a clean UX, robust sync engine, and error handling. I'll use Flutter for mobile and C#/.NET for Windows, ensuring efficient uploads/downloads and reliable sync. Let's deliver polished apps with auto-sync, virtual drive, and selective folders. Your project fits perfectly with my expertise. Looking forward to discussing further! Thanks, John Allen
€1,000 EUR in 10 days
1.0
1.0

Hi my next Client, You don't have to pay if you are not happy with your requirements. I can deliver a top-notch sync and cloud storage app for Android, iOS, and Windows, meeting all your detailed requirements. With 15 years of experience, I offer a seamless, clean UX and robust error handling. Let's discuss your project more - I'm eager to assist. While I am new to freelancer, I have 15yrs of great experience and have done major projects off site from this Platform. I would love to chat more about your project! Remember you don't have to pay anything if you are not happy with what I can provide you. Regards, Daniel van Vuuren
€1,000 EUR in 30 days
0.8
0.8

Hello Pedro, I have checked your job description and I’m confident I can complete exactly what you need. With extensive experience in cross-platform mobile development using Flutter and C#/.NET for Windows applications, I am well-equipped to deliver the polished, Google Drive/Dropbox-level experience you’re seeking for Tred. My expertise includes efficient sync engines, conflict handling, and building intuitive user interfaces. I can ensure reliable uploads/downloads, background syncing, and seamless folder management, aligning with your tech preferences while maintaining a focus on clean architecture and documentation. I would love to discuss my approach to implementing selective backup, strong error handling, and essential features like the virtual drive on Windows, along with the mobile specifics you mentioned. Thanks, Andrii
€1,000 EUR in 9 days
0.0
0.0

Hello, Now Meta is your company, leveraging a decade of proven expertise in Matching Job Skills. I have attentively reviewed the project’s requirements for the development of Cross-Platform Cloud Storage Apps for Tred on Android, iOS, and Windows. Our team will follow a meticulous process to ensure the successful delivery of the project. We will focus on implementing selective folder backup, auto-sync, reliable uploads/downloads with resume capabilities, background sync, and scheduling features. Additionally, we will incorporate built-in preview functionalities, secure sharing options, and a Windows app with a mountable virtual drive. I invite you to start a chat for a more personalized discussion to further explore how our approach aligns with your project needs. Regards, Now Meta
€750 EUR in 7 days
0.0
0.0

Hello Pedro Maria A., I would like to grab this opportunity and will work till you get 100% satisfied with my work. I'm an expert who has many years of experience on Mobile App Development, iPhone, Android, C# Programming, Windows Mobile Lets connect in chat so that We discuss further. Regards
€1,500 EUR in 7 days
0.0
0.0

Dear Client, I am confident in your project. I am available to start working with you immediately. I will prove myself through my results. Thank you, Yurii
€750 EUR in 7 days
0.0
0.0

Hello, Good morning . I’m excited to help you with Cross-Platform Cloud Storage Apps for Tred (Android, iOS & Windows) — Auto Sync, Selective Folders, Virtual Drive! I have solid experience in C# Programming, Android, Windows Mobile, Mobile App Development and iPhone and have done similar projects. My Approach: I break every project into clear, realistic milestones, communicate proactively, and deliver well-tested, efficient solutions that are easy to maintain and scale. Scope of Work (SOW): In-depth requirement analysis Design and development with modern best practices Rigorous testing and performance optimization Secure deployment and clear documentation Ongoing support if required I’m confident I can help turn your ideas into a robust and successful product. Let’s discuss your goals and how I can best contribute to your project. Best regards, Roshan J.
€1,250 EUR in 7 days
0.0
0.0

Hello Pedro Maria A., I understand that you are looking for production-ready cross-platform cloud storage apps for Tred on Android, iOS, and Windows with features like selective folder backup, auto-sync, virtual drive, and efficient sync engine. As an experienced mobile app developer with expertise in Android and iOS development, I am confident in delivering polished apps that meet your requirements. I have a proven track record in developing mobile apps with clean UX, reliable sync capabilities, and robust error handling. I plan to use Flutter for mobile app development and C#/.NET for the Windows desktop app, ensuring efficient delta uploads, low CPU usage, and clean architecture. Effective communication and collaboration will be maintained throughout the project to ensure timely delivery of quality work. I am committed to providing you with a seamless user experience and meeting all the specified criteria for acceptance. Thank you for considering my proposal for this project. I look forward to the opportunity to work with you and deliver exceptional cloud storage apps for Tred. Best regards.
€1,100 EUR in 7 days
2.5
2.5

Guareña, Spain
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