Customizing the tab bar
The tab bar sits at the bottom of nearly every view in the iPhone and iPad apps and functions as a group of shortcuts to the pages you use most. And because everyone is different, you can customize what appears here.
If you want to swap out the default shortcuts with others that you use more often, tap "More…" to bring up the rest of the tab bar options and then tap Edit in the top right corner.
On the next page, you'll see the all available icons for the tab bar. To add, just drag the icon to the tab bar and release. The new icon will appear in there immediately.
Once you're finished, tap "Done".