The device is not reliable. It often fails to connect. The cube just not respond to the app, like a brick. I found that I can poke the small hole next to the USB port to reset it. The manual does not mention this hole, but talks about a "reset button". I guess it was an older design? This also happened during one of my tests, that the device just disconnected after the cartridge was inserted. I ended up have to cancel that test and waste the cartridge.