When Apple released iOS 4 last year, iPhone users were given the ability to multi-task. However, Apple keeps the apps you have been using running in the background of your smartphone, which can slow down your Apple handset as well as draining the battery quicker.
Here's how to check and subsequently close applications that are running in the background on an iPhone.
Press the Home button twice in quick succession. This will display the multi-task bar the details all apps running in the background
To close an application, press and hold its Icon. The image will begin to 'wobble' in a style similar to that adopted when you are removing apps, and a minus sign will appear.
Push the minus sign to close the application. When you've closed the applications you want to, press the home button to exit the multi-task bar.