Japanese Green Tea Shop
The app does what it says. It worked on my Iphone 8, my 8Plus and my Ipad Mini (R).
Overall it's a good app. Great idea for those that do not know how to do it yourself (just google it), or if you just want to save time. I'd be willing to pay a one time fee of $10.00 for this, even $.99 a month. But I do not see any reason for a monthly charge of $4.99 for such a simple tweak.
Again, it works, but I think it should be a one time fee (or limit the number of times you can edit/change your icon). I may reinstall if they reduce the price. I'll uninstall it for now.