When you plug your device in iTunes, you may notice a yellow section of data on your device labeled "Other." This can either be a very small number, which is normal, or a very large number, which is not. Having a large number could mean something happened when syncing music, video or apps, and it can cause the system to not recognize the correct app to put the information under. To fix this, follow the steps below:
Step 1) Select your device in iTunes and go to the "Apps" tab. Uncheck "sync apps," then press the sync button in the bottom right corner.
Step 2) After it is done syncing, go back to the "Apps" tab of your device in iTunes and recheck "sync apps." Then proceed to sync.
Step 3) If that did not fix the problem, repeat those steps on the Music tab and the Movies/TV Shows tab.
Step 4) Last but not least, if those solutions did not solve your problem, then you will have to initiate a restore on your device. To do this, follow the guide posted here. This will fix all problems associated with the "Other" data on your device.