If you somehow lose the applications on your iPhone, it can take a lot of time to download them again and install them on the device. It can also be inconvient if you find yourself without a tool you have grown accustomed to using. If you have synced your iPhone since you added the last app, you can restore the apps using your computer. If you did not sync it, you must reinstall the apps one by one by using the App Store on your phone.
Using the App Store – Power on your iPhone.
Open the “App Store” by pressing its icon.
Enter the name of the application in the “Search” box.
Press the price, then press “Buy” if it is a paid application. Press “Free” and “Install” if it is a free app.
Enter your iTunes password in the pop-up box. Because you already bought the application, you will be told to download it for free. Select “OK” and the application will be installed.
Using iTunes on Your Computer – Power on your iPhone.
Open iTunes on your computer.
Connect your iPhone to your computer using the sync cable.
Select your iPhone under the “Devices” column in iTunes. It is located on the left of the page.
Open the “Applications” tab. All of the apps you downloaded will be listed. Select the boxes for the apps you want reinstalled. Open the “Summary” tab, then select “Sync.” The apps will be reinstalled.