Solfeggio frequency

It's alright the frequencies are decent but the apps cuts out when I try to run in background. Nice effort though

What a lovely idea -- an app like this. And how much lovelier it would be if it worked properly on my phone without stopping or crashing nearly every time I switch to another app (usually cutting off the sound it generates or once even leaving it on and making it tricky to shut it off) as well as at other times and if the volume sliders worked even when their frequency is off. And how about that playing of (supposed?) healing sounds while showing nasty ads of toy guns for children....