Chess Repertoire Trainer

I've tried backing up all the games I've entered but I can't find the file anywhere on my phone. Is there any way to check that the back up was successful? I've literally spent hours entering different opening lines

I start to add moves of a variation and after a while (it never happens after the same amount of moves) it is impossible to do anything (adding moves, adding graphics...). Everytime, I have to go back to the menu, select the opening I want to edit, find the position and complete the variation... It is very frustrating. Can be this problem be fixed?