Opening the app it lags tremendously. When I press the start button to begin a level, I have to wait for approximately 5 minutes before it actually starts. Then when i finish it, it shows me I made the correct choice, and let’s me wait another 5 minutes before i can continue to the next level. I’m just stuck on one screen the entire time I wait. When I close the app, even with my iPad shut off the music keeps on playing because of the lag. I have this problem with all the brain test apps made by this developer. I have no problem playing other games, it’s just these games. So no, it’s not because of my device it’s a dev problem.