Applications are bought from different stores including the iTunes through the iTunes on a computer and are downloaded to the apps library on the iTunes, for one to sync apps to their iPhone there is need for the apps to show in the iTunes by clicking on apps at the left hand column then follow the simple steps on how to sync iPhone apps. First connect the iPhone to a computer and launch iTunes to select the device in the left hand column click apps tab and check sync apps. One can select the apps they desire to sync at the left hand column, if one chooses to select all the apps this is done by clicking on the checkbox while holding down the control key on the windows or the command key and one can organize their apps into folders using iTunes for easy access.
After the selection process and changes are made click on sync to be able to transfer the apps that have been selected to your device. It is important to note that while following the steps on how to sync iPhone apps, any changes made on the device while it is still connected to iTunes there is need to disconnect it from the computer and reconnect it before any changes are seen on iTunes.