One of my pool related side projects is DrawShot for iOS.  It's an iPhone/iPad app that lets you draw a pool shot and share it through Facebook, Twitter, email, etc.  It's free to use with up to five saved drawings that you can go back and edit later.  There is a small fee (Update: DrawShot is now totally free!) to upgrade to the Pro version which will allow you to save as many drawings as you want.  Note that you can export as many images as you want and you can even delete one of your five saved drawings to make room for a new one, so other than saving a lot of editable drawings, the app is full featured for free.