Instarocket is a touch based program to perform early conceptual sizing on a 2 stage liquid launch vehicle.
Similar mathematics are found in ZPFCs (Zero Point Frontiers Corp) Level 0 Launch Vehicle design Process.
Instarocket is ideal for college or professional engineers needing a rough sizing solution for a 2 stage LV.
Typical results are achieved in less than 5 minutes.
App: https://itunes.apple.com/us/app/instarocket/id455325630