Download the PDF file and print as many sheets as you need, then start sketching out your new app interface, interaction and screen flow. Both are US standard 8.5” x 11” sheets of paper, complete with grid and guides to help you quickly get your ideas down.
An analysis of when to use a menu like the Path 2 sharing menu – This article does a good job of stating when and when not to you would like to use that type of pop out menu — it definitely isn’t suitable everywhere.
Edward Kim writes an interested (albeit unverifiable) post about how much money he made from app sales. Read it here: “My last Android app sales figures, and why its still great to start a mobile app business. – Edward Kim.”