Orbital Yards lets you create and store a collection of spacecraft and starship designs using the rules in Book 5: High Guard (Second Edition), as amended by the Consolidated Errata and Adventure 05: Trillion Credit Squadron. It doesn't support multiple weapon types per turret, collapsible fuel tanks, or spare systems.
I did add the ability to adjust stateroom allocation in starships between normal, full staterooms for all officers, and full staterooms for all crew so you can build really roomy designs.
Compatible with iPhone, iPad, and iPod Touch. An iPad is highly recommended, as this gets you a completed IN Form 3 with Universal Ship Profile, which I couldn't squeeze into an iPhone form factor.