Replacing Digital Touch icon with Stickers would be super useful, especially if the percentage of DT users is so low!
The shadows on the nav bar feel a little inconsistent with Apple design, as well as the exclamation mark on the proposed sticker icon.
I think the scrolling sticker icons at the bottom could clutter the screen, and may be too small to comfortably tap.
My initial thought is wider pill style icons on the nav bar, with lots of breathing room and max three in view at once would be easier to access without feeling like playing a game of operation when selecting the pack you want!
Awesome article, keep it up :)