The download button opens the iTunes App Store, where you
may continue the download process. You must have iTunes installed with an
active iTunes account in order to download and install the software. This
download may not be available in some countries.
From STAAPS Interactive:
Add as many counters as you need to the screen and position them to your liking.Tap the small minus circle to reduce the counter by one, and the big circle to increase it by one.Use the pencil button to scribble notes or labels onto the screen.Multi-Touch support so you can increase multiple counters by tapping different fingers, or work with another person with your own counters on the same screen.Too many counters on the screen? Just drag one to the trash button and it's gone for good.Practically no limits! The counters can go very, very far into both positive and negative numbers.