Frequently loses games in progress! – Super Sudoku - Brainstorming!! Review

Generally interesting sudoku variants but I have two big complaints: often loses games in progress while App is in background, which is super-frustrating, and does not automatically remove temporary numbers (and when all of a number is filled in, you can't even manually remove corresponding temporary numbers!).
Review by PaulAsimow on Super Sudoku - Brainstorming!!.