One thing that often happens on Android powered smart phones is that when you install a new app, it automatically removes another icon and takes its place. If you want to get rid of this problem, just hold the icon of the app that you have just installed, hold it for a second , then drag it to the place of your choice. And if you want to place it on the previous or next slide instead of the current slide, then grab the icon and move it around , when the slide changes, set it on your desired slide.