Pythonista - graphic performance

[Einehordebedrohenie]

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Good evening! I wrote a little game in Pythonista. It is just like a chess game. The users are moving figures over a chess board with a touch_moved method from the ui.view library. The figures are little png-files with 384x384 pixels. It works, but the framerate looks like 15fps or so when I drag a piece over the screen. Any ideas how I could improve that?

Thank you!