Need to improve mechanics of the game

The biggest turn off of this game is the double tapping to turn a solid block into an X. You need to have a button on the bottom of the screen that lets you switch from solid blocks to Xs when you touch. The way it is now is annoying and frustrating. PLEASE DO THIS. It would improve the game a 1000%

Rydolea about Nonograms CrossMe, v2.1.06