Filed under: Accessories , Developer , iPhone Want to sketch out your iPhone apps? There's a notebook for that. App Sketchbook is a pretty nifty notebook for iPhone developers who want to sketch out their products out on paper as part of the brainstorming process. App Sketchbook has three pre-drawn, full-sized iPhone templates per page with ruled lines beneath for notes. A pixel ruler runs alongside the template. You can use them in conjunction with iPhone UI stencils to get your ideas