I don't get 2 things: How does it tell you if you've put in a wrong letter? I tried doing that on purpose to see if it'd change color or flash a msg -- nothing.

Also, when I finished the puzzle, nothing happened -- it didn't say "puzzle completed" or any other msg, or flip to the next puzzle.

(Granted, it took me a few minutes to figure out that the clues were on swipe horizontal tracks.)

When doing a Shortyz crossword, you have the option of having the app show or not show when you have entered a wrong word/letter.

To receive a warning on a wrong letter input, have a crossword puzzle on your screen, Tap on the 3 stacked dots in the upper right of the screen. The first option on the menu that opens is "Show Errors". Tap that and whenever you input an incorrect letter, it will show up in red. To turn off the option, tap the 3 stacked dots and the first option on the menu will be "Hide Errors".

The reason you're not getting a message indicating your success at completing a puzzle is because you have an incorrect answer(s) somewhere.

In this instance, you can also use the "Show Errors" option AFTER you've completed a puzzle. The incorrect letter(s) will be in red. When you correct the final red letter, the "success" message will appear."