Thank you for the feedback!
I wasn't aware of the problem with the wobbling letters but I think I can understand it. I think the way ren'py handles some animations can be taxing on devices with limited processing power like phones.
I will look into this and consider implementing something to get around it in order to prevent this problem from happening! I have some ideas.
If anyone else playing on Android is going through similar issues with this or other animations, I would like to know about it and I'll work to improve it in future updates!