Same issue here with ipad air 2, ios 14.8.
The app has been downloaded here in the first page from iosgods, retried the install process 2 times (also the download), one with the original app installed, one without that.
In detail:
1) the app start
2) the iosgods popup request the iosgods access, it seems to work (after login, the icon become transparent and it smothly move to the right-middle of the screen)
3) simply piano asks for his login sending a code by e-mail
4) just after the login, the app crash (auto-closing itself)
Retrying the same process both iosgods access and simplypiano access are skipped (correct; credentials have been saved) but the app crash after some seconds of loading and after accessing.
Can someone point me to a solution?