You can make an app for the iPhone for free (or almost free), however there are already multiple loan payment calculator apps for the iPhones. You may still choose to make another one if you want.
Songify for the iPhone and iPod I think
It's currently out on the App Store.
nthin
There is a free iTunes App called My Contacts backup. The app allows you to export all your iPhone contacts and to send it to yourself via Email, making it quite easy to import the contacts on the new iPhone.
you get a ringtone making app and follow its instructions
Altough there is no radio application on the iPhone, you can download it. with the "App Store" program in the iPhone, you can download an app that gives you the opportunity for listening to radio.
There is no way to do that. If you jailbreak your iPhone there is an app on Cydia that does that.
Yes, there is an Answers App for iphone in the apple store
for an iphone there's already an app called safari which is the internet
Yes, you can find your lost iPhone with an iPhone app. However, you must have access to another apple product with the same app to locate your lost iPhone. It's called FindmyiPhone in the app store, and it's free. All you do is make an account. Let's say your iPhone is lost, all you do is sign in with your account with another device with the same app and the app will do the rest. Its quite amazing.
The GoPro Quik app saves files on an iPhone in the app's internal storage.
It already did. The Farmville App is available on the App Store now.