ShortHand is a web app — nothing to download. Follow the steps below for your device and it will live on your home screen just like a regular app.
Open Safari and go to getshorthand.app
Tap the Share button at the bottom of the screen (the box with an arrow pointing up)
Scroll down and tap "Add to Home Screen"
Name it "ShortHand" and tap Add
ShortHand now appears on your home screen like any other app — tap to open!