They appear when you install more than 15 apps, no way to remove them unfortunately. (For you as you don't want them)
I actually miss them, I'm now back on NoDo and have a long scroll to perform through my app list. Was much quicker with the Mango alphabet tiles.
Oh and a warm welcome to WPC
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)