Simple. Simple. Simple. That's the common denominator in all of the apps that made our must-download list, and Sporty's wonderful electronic E6B app hits the bull's eye in this regard. This handy app includes all the classic utilities any pilot could want, plus a number of features that pros will appreciate, including Mach speed, top of climb, specific range, required rate of descent and more, all presented on an easy-to-use app interface. The electronic E6B also includes a clock/timer that always shows local, home and Zulu time, and which can count up or down, making it useful for timing approaches or knowing when to switch fuel tanks. Best of all, the app works with all versions of the Apple iPad, iPhone and iPod Touch.