SmartLaunch is a rocket launch simulation app that gives on-the-spot information about the initial moments of a planned launch. Specifically, given a few details about the rocket and the motor, it will give the speed at which the rocket will leave the launch guide, the angle of attack of the rocket with any crosswind, as well as the thrust-weight ratio based on the initial thrust of the motor (not the average thrust). Using this information, the rocketeer can judge whether a specified motor may result in a stable flight under the given conditions.
The app also gives the expected apogee altitude and coast time for the proposed flight.

Version 1 features:

User specified units (metric, standard)
Set launch angle by tilting the device, either up against launch guide or by camera view
Set launch site altitude by GPS (if available and Location Services allowed)
Database of over 800 commercial rocket motor thrust curves
Remembers multiple rockets and easily switches back and forth
User can decide which motors they want to see in the list - by diameter, impulse class or manufacturer