C172 Performance computes all the useful performance numbers for flight planning for Cessna 172S and 172N aircraft. It includes calculations for takeoff, landing, climb, cruise, descent, instrument procedures as well as emergencies. It also includes an interactive hold calculator, a risk analysis tool, and an emergency glide distance calculator that handles head and tailwinds.
C172 Performance is also available on other mobile devices and as a WebApp (an App that runs in a browser) that runs on a variety of platforms (PC, Mac, tablets, phones). The cloud sync feature allows flight planning profiles entered on any device to be synchronized with your other devices when connected to the Internet.
C172 Performance is a free, open-source development effort and has Apps and WebApps for other aircraft. See http://pohperformance.com for complete details.