I believe a lot Android devices still don't support Bluetooth Peripheral mode so relying only on BLE might exclude a lot of Android users.
But luckily, Wi-Fi Direct (also known as Wi-Fi P2P) is supported very well in all most every existing Android devices (Android 4.0 +)
Why not also include Wi-Fi Direct into the application to enable the direct communication between 2 nearby Android devices?
I believe a lot Android devices still don't support Bluetooth Peripheral mode so relying only on BLE might exclude a lot of Android users. But luckily, Wi-Fi Direct (also known as Wi-Fi P2P) is supported very well in all most every existing Android devices (Android 4.0 +) Why not also include Wi-Fi Direct into the application to enable the direct communication between 2 nearby Android devices?
Android Devices <-> iOS Devices (BLE) iOS Devices <-> Android Devices (BLE) Android Devices <-> Android Devices (BLE + Wi-Fi Direct)
The following is a Github repo demonstrating how to use Wi-Fi Direct to send greetings between 2 Android Devices. https://github.com/SeanXu1984/WifiDirectGreetings