@RiffelLeonie uninstalling will remove your save files. You can manually back up your save files though with a file manager app of some kind if you need to uninstall. Saves are located in android/data/com.chucklefish.stardewvalley/files/saves
Yesterday's patch that fixed several things including NPC locations & stuck animals, is out on iOS now. Please make sure to update. It might take one night in-game before you notice some of the issues being resolved. Android should also have a fix for the menus not closing.
We're going to continue investigating and fixing any bug reports, and also start focus attention on the UI/scaling issues that many are experiencing, especially those who have high resolution displays like on iPads and other tablets.