Set the app to be restricted to PIN access only, no bio unlock, can't compel that info without a warrant.

Then app dev has you set up two pins: The first is the same as the phone unlock pin, which is the app self destruct (or just doesn't decrypt data) and then a different pin that does the data decrypt, so this way if they compelled your pin and then try to open the app with the same one, oops, phone glitch, data gone.