When it tells you to hide, cancel any actions and press the arrow down on the left side of the screen until you're at the bottom, then press the ninja at the bottom middle
Not that it matters to me because I just use WinZip, but you can indeed upload APK files if you'd like to, you also don't need to include the idsign file as that's just generated on export. Just a few tips for ya, keep up the great work!
Press the down arrow on the left so it moves you all the way down, then press the ninja icon that's at the bottom middle of the screen. Press it again to come out of hiding