Android & iOS Bluetooth Design Support

***THANK YOU FOR REVIEWING OUR POST. ALL CANDIDATES WILL BE CONSIDERED ONLY VIA UPWORK. DO NOT CALL, EMAIL, MESSAGE OR SPAM US OUTSIDE OF THE UPWORK PLATFORM. VIOLATORS WILL BE DISQUALIFIED.*** We are seeking a skilled freelancer to assist with designing Bluetooth features for our Android and iOS apps. The ideal candidate will have experience in mobile app development, particularly with Bluetooth technology, and be able to provide innovative solutions to enhance user experience. Responsibilities include collaborating with our team to implement Bluetooth functionalities and ensuring seamless integration across both platforms. We have an existing published Flutter app with Firebase integration and BLE communication already implemented using flutter_blue_plus. The app scans, connects, reads/writes BLE data, and communicates with our hardware. We are looking for an experienced freelance developer to help improve background BLE behavior on both Android and iOS. This is not a basic Flutter app development task. We need someone who understands Flutter plus native Android/iOS BLE background limitations, as well as app store rules, limitations and workarounds. Required Skills Strong native Android development experience using Kotlin Strong native iOS development experience using Swift Hands-on experience with Bluetooth Low Energy communication BLE scanning, connection, GATT read/write, notifications, and reconnection handling Android background BLE handling using WorkManager, foreground services, PendingIntent scanning, or Companion Device Manager iOS CoreBluetooth background handling, app lifecycle management, and background-safe data upload Firebase / Firestore / Google Cloud Functions integration Experience working with IoT, wearable, medical, or hardware-connected apps Project Scope Implement BLE device discovery and connection Read telemetry data from BLE characteristics Handle background and terminated-state behavior as much as the OS allows Sync telemetry data to Firebase / Firestore Add retry logic, local buffering, and error handling Provide clean, maintainable code and basic technical documentation