From Delta Tao's website:

Spaceward Ho! is a strategic game of awesome scope. You control the entire military and economy of a spacefaring race. Your goal: explore and colonize the galaxy. Unfortunately, you are not alone. ...

Classic Star Trek game for palm OS. Choose your mission and go battle Klingons, don't forget to refuel when you get to a starbase!

This is shareware but you can play through to Lt Commander without registering

Warfare Incorporated is a real-time strategy game in which players must gather and manage resources, develop bases, and deploy troops to defeat a variety of enemies across a story-driven single-player campaign as well as local multiplayer over WiFi or ...