iPhone has problem downloading apps?

[Zach]

I am trying to download apps yet it says I need iOS 4.1 or higher when I have 4.2.1. It also won't let me download the updates for Facebook or Twitter.
I have an iPhone 3gs and all of the apps say they are compatible with the iPhone until I try to download them and it says "This App is not compatible with this iPhone"

Any help will be appreciated!

[Brittney]

I think you might want to update or upgrade your phone if you want those apps. The 3Gs is quite old and a bit outdated. Don't get me wrong, I'm an apple fan myself. Same thing happend to my iPod touch 3rd Gen.
Excuse me if I'm wrong. Wish you the best!

[?]

Hello!
Even that your iPhone 3GS has iOS 4.2.1 and the app states 4.1 or higher, some apps can't run on previous generation models, the application your running probably has high use of graphics and performance and newer models have better performance. Check the applications page on the App Store and read the description and what models are compatible with the application you want to download. It might say "Only runs on iPad 2, iPad 3rd generation, iPhone 4, iPhone 4S, iPod 4th generation, will not run on earlier models".