There are 3 repositories under android-ble topic.
BLESSED, a Bluetooth Low Energy (BLE) library for Android
The app for BLE ether monitoring tracks your environment, finds some devices, makes relations between devices around you, and tracks devices' movements.
A simple, lightweight library intended to take away some of the cruft and tediousness of using the Android BLE.
一个用于扫描BLE设备的安卓框架(A library for scanning ble device on android)
The *.aia project for MIT App Inventor 2 and the arduino sketch for the Adafruit nRF52832 to communicate via Bluetooth Low Energy (BLE)
A library that makes working with Bluetooth LE on Android .
An Android Bluetooth Low Energy GATT Server Library with RxJava3 interface
Android scaffolding code to scan for BLE devices
An Android library providing Wrapper APIs to interact with beacons.
My bachelor's degree final paper/project - Infrastructure to facilitate communication with objects at sea