iOS 7 update not shown in Software Update When I try to update my iOS 6.1.6 it says it's up to date and it's been like that for five months. However, every App that I want requires a minimum of iOS 7.0.

I have an iPhone 3G.
If it's running iOS 6 it's a 3Gs, not 3G, as the iPhone 3G is not supported by iOS 6. Either way, neither device is supported by iOS 7, so you can't update to iOS 7.