I very much appreciate that this game is accessible and free, so I don't know if you are considering further development. If so, my top request would be that the winning screen would appear once all non-mine squares have been cleared. More advanced users like the challenge of playing without marking the mines, but in this version, all mines must be marked in order to "win." Along that line, I would prefer an option where clicking/double tapping in VoiceOver would automatically open the square. Perhaps flagging could be a tap and hold? I just found it distracting to have to select a square, go to the bottom of the screen to select the action, then get back to where I was working.