Want to Try Manual Tile Counting?
Tile-tracking sheets are free for the downloading at most Scrabble Club sites worldwide.
For a comparison of methods see this article: TileCounter vs. Tracking Sheet
Tracking and counting tiles is officially recognized and sanctioned by the National Scrabble Association, so you can check out almost any Scrabble club worldwide.
You'll save 1.99, and maybe even see some interesting photographs.
You won't find much really tailored for mobile app games—being paper—but that does make it easy to fold them up and stuff them in your pocket.