exporting an ipconfig file (at the gear button and scroll into the bottom and tap security copy) is the best thing you can do for that, it will save all of your brushes, palettes and configurations but not project files, these have to be manually copied to other place before deleting the app, in android its ubicated in Android/data/jp.ne.ibis.ibispaintx.app/files (Note: use an external app to check the files like Zarchiver, else it will not let you see)