are you sure there isnt a filter or view setting somewhere which you can change. I would assume that by default it removes an app from the search results if it thinks you dont want it. If you are determined you want to get to the bottom of it then have a look at this
http://www.eightforums.com/tutorials...ndows-8-a.html
or if you want a quick fix hold the windows key and press r and then type wsreset.exe and hit enter
Don't ask me anymore because I don't use windows 8