With Apple iTunes, you have unlimited access to download previous music, movie and app purchases anytime you like. This comes in handy if you have lost your files on your hard drive or wish to easily download the content to a new device. Here’s how.
From iTunes on Computer
Open iTunes and select iTunes Store.
On the right menu, click the Purchased link.
If prompted, type your Apple ID and Password, then select Sign In.
Select the type of item you wish to download at the top-right part of the window. Choose Music, TV Shows, Apps or Books. You can also choose to view All or items Not in My Library.
Select the Cloud icon next to the item or the Download All button located at the lower-right part of the screen to download the item(s) to your computer.
From iPhone, iPod Touch, or iPad
Music, Movies, and TV Shows
Open the iTunes Store app.
Select More at the bottom of the screen.
Select Purchased.
Choose Music. Movies, or TV Shows.
Select the All or Not On This… option as desired at the top of the screen
Select the item you wish to download.
Tap the Cloud icon next to the item to download it to the device.
Apps
You can download purchased apps right to your mobile device.
Open the App Store app.
On the iPad, select Purchased. On the iPod Touch and iPhone, select Updates.
Select Purchased.
Tap the Cloud next to the apps you wish to download.
How to backup all iPhone Data to PC or Mac?
With the Phone backup tool you can easily backup all iPhone Data to PC in one click.