We have tried working with nrF UART android source code from Github, it is not working, we have connectivity issue. it is working fine with the uart application which we have downloaded from playstore.
Please send us latest nrF UART android source code.
Adding to above query,
I have downloaded "nRF UART v2.0" source code from GitHub and installed in my phone after building the app. For this app, when I try to connect Nordic board, it is not visible. Refer the attachment ,