How to Update an App from the App Store on an iPhone

Are you getting updates to your apps when you open iTunes? If you seem to never update your iPhone and apps keep crashing, you can learn how to update your apps right from your device by reading and following the directions in this article.
STEPS

1

TAP THE "APP STORE" BUTTON. It should open up the top menu (if you haven't updated or searched the store itself yet.)
Wait a moment for the App Store to open. It will find any available updates and if an update is found, it will be shown to you as a red circle.

2

TAP THE "UPDATE ALL" BUTTON FROM THE BLACK BAR ON THE BOTTOM OF YOUR DEVICE\'S SCREEN.
Tap the "Update" button, if you'd like to update each app separately.

3

TYPE YOUR APPLE ID\'S PASSWORD INTO THE BOX.
On iOS 6 and above, you'll only have to type your password into the box once after upgrading, then, succeeding app updates will not require this step.

4

WAIT A FEW MOMENTS FOR ALL THE UPDATES TO INITIALIZE, DOWNLOAD AND INSTALL.
TIPS
The App Store automatically lets you know that there is an update with a number on the icon. You just have to go into the store on your device and download it. It all happens in less then minutes.
With iOS 6 and above, you shouldn't need to constantly open the App Store to check for updates. The App Store is pretty good at remembering to check every few minutes and deliver the results back to your device in real-time without much delay.
You can also sync your device after updating your apps in iTunes. However, this is the easiest&simplest process to do, as long as you're not worried about going over the bandwidth or 3G data rates (which most people have unlimited data plans).
WARNINGS
This process works for any iOS device (iPod touch or iPhone) level 4.2.1 or lower. This will no longer work in iOS 5.0!
THINGS YOU\'LL NEED
any iOS device
wireless (always on) Internet device
AppStore app (default, preinstalled, undeletable app)