[halflings]

No permission seems to be required to listen on a call being done:

https://developer.android.com/reference/android/telephony/Ph...

There's one permission (READ_PHONE_STATE) required for some other methods, but it is different from the permission to initiate a a phone call.

[bcook]

READ_PHONE_STATE is precisely what the app in question uses.

https://github.com/harjot-oberai/MusicStreamer/blob/master/a...