I just installed this app ( SINE Isochronic Entrainer | F-Droid - Free and Open Source Android App Repository ) and noticed strange behaviour - it doesn’t contain any data in it. Which is very strange. Instead it suggesting to download all sound data (emphasizing on word “free”).
But real concern arised when I’ve checked XPrivacy settings. It showed that this “entrainer” also tried to use tracking. As long as tracking prohibited “entrainer” doesn’t even downloading data (claiming there is no internet).
It’s funny that app page states “Respects your privacy” among it’s features.
Please, check it’s functionality and, if spying is proven, remove app and ban author.
That’s very silly - to use tracking while claiming respect to privacy.