Noting that you are in the USA, Foreflight is my first choice. AOPA and DUAT apps are also very useful. You will see mention of SkyDemon, a stunning UK-based product which provides almost world-wide coverage and an amazing array of services too numerous to cover. It also manages to get around some of the traditional limitations of the iPad by the use of Cloud computing. You can prep on a PC and sync to the iPad now.
I bought an original iPad 3G now dedicated to flying, bought a plastic back off eBay for a couple of £ and cut slots to fit a velcro strap for a leg mount. Never have trouble with GPS reception (Low wing AC) or the screen or overheating or battery life.
I find the IFR plates in pdf helpful as you can zoom into figures when I couldn't read the paper plate font size in turbulence.