I love this app, but some spectators see that it doesn’t behave like a normal calculator. When you type a number and hit the multiply button, a normal calculator highlights the button and then if you punch in a new number, then hit a button, the running total is displayed (might be a problem for some tricks). Anyways, some spectators who use calculators regularly will not be fooled by this. They’ll know something is up. It’s similar to the +0x1c force, but a little better, since this app at least continues to display the last number, but +0x1c shows a “0” every time you hit multiply or divide.
Also, it would be good if the app icon did not have the word “force” on it. If it just said “calculator”, I could have the spectator open the app.
Thanks for a great trick though. Very powerful mentalism effect.