This app was mentioned in 2 comments, with an average of 1.50 upvotes
Garmin Pilot (EFB)
Takeoff (METAR / TAF interpretation app, love it!)
Kindle (for waiting around at FBOs...)
Not to put a damper on you rolling your own, if nothing else it's a fun project, but it sounds like Takeoff has at least most of the things you're looking for.