Pocket Planes -- which has seen 2.5 million downloads to date from the App Store -- is a free-to-play tycoon-style game with premium currency, but it is easy to play and to advance without purchasing any currency. NimbleBit's Tiny Tower [App Store] works similarly, and is a perfect game for the taller screen on the iPhone 5.
The Mac version is a near-identical port from the iOS version, complete with massive interface elements, though some parts -- like the flight map -- have been optimized for the larger screen on the Mac. The iCloud syncing between the iOS and Mac versions should make it easy for gamers to continue playing no matter which platform they're using.
Pocket Planes is a free download for the iPhone and iPad. [Direct Link]
Pocket Planes for Mac is a free download from the Mac App Store. [Direct Link]