After saving a file You have to press the back key two times to exit or press on the menu then press on settings then press on Exit (three presses) to quit the app. It would be easier to have another option in the Files icon at the top in addition to Save, being (Save and Exit) or (Save and Close) . Another option is moving the exit icon from settings to the top of the screen next to files with an option to save first (yes or no), if any changes, were made to the file.