Apple launched family sharing- a app by which you can stay in touch with your family or group of people and share purchase iTunes, iBooks as well as App Store items.
Open the device and then go to the settings and then iCloud.
Click on the SET UP Family Sharing and then click on GET STARTED.
In the third step just confirm that you are a part of family organizer. Use your Apple ID to sign-in and then follow the instructions given on the screen.