SolarWars is a turn based orbital ballistics game in which you launch a variety of interplanetary missiles to fend off incoming projectiles as well as take out any threat. Between battles the player gets to choose ever more powerful upgrades to increase their arsenal and strategical/tactical abilities.
Playable in singleplayer or 2-player-couch-coop (multitouch)
SAS Labs Project
High-Performance Orbital Ballistics
Deterministic Simulation and Prediction