iPhone + iPad
Round & round
The alphabet is more versatile than double-sided sticky tape. Depending on where you are in the world, it can be left to right, right to left, top to bottom, bottom to top.
All that's missing is circular text. And even that exists now, thanks to CircleText. Write circular messages on all your photos in all fonts and sizes. Usually costs 3.59₺ but now it'sFREE!