For Seniors: Update Apps on Your iPhone 4S
App developers update their apps all the time, so you might want to check for those updates for your iPhone 4S. Assuming Notifications Settings are set up to alert you to updates, the App Store icon on the Home screen will display the number of available updates.
If you have turned this setting on, tap the App Store icon on the Home Screen. At the bottom right of the App Store screen is an Updates button, which will indicate the number of updates available, if any, in a red circle.
Tap the Updates button to access the Updates screen and then tap any item you want to update. To update all, tap the Update All button.
On the app screen that appears, tap Update.
You may be asked to confirm that you want to update, or to enter your Apple ID and then tap OK to proceed. You may also be asked to confirm that you are over a certain age or agree to terms and conditions; if so, scroll down the terms dialog and, at the bottom, tap Agree.
In iOS 5, Apple introduced the capability to download multiple apps at once. If you choose more than one app to update instead of downloading them sequentially as in previous versions of the iOS, all items will download simultaneously.
If you have an iCloud account and update an app on your iPhone, it also updates on any other Apple iOS devices automatically and vice versa.