With this app you are able to start every other app by do a long-touch on the search button. You could use this to start you favorite app like Facebook or a task manager.
Easy installation:
* Download and install the app
* Choose preferred app
* Now do a long touch on "Search"
* Done
In case you like this app, i would be glad about a donation (see "About")
Donator-App & Features: https://play.google.com/store/apps/details?id=de.defim.apk.searchbutton.donator