App page sorting after app uninstall
Chances are you are using a stock launcher (maybe Samsung's TouchWiz) that leaves empty spaces when you uninstall an app.

If you are using Samsung Galaxy S4 (using stock launcher), you can go to the Apps screen, and click on left menu key &gt; View type &gt; Alphabetical grid. If you are not on an S4, see if you can find something similar to this.

If you do not have the Alphabetical grid option, you can install a 3rd party launcher like Nova. Nova can sort your app drawer alphabetically.