Question

I’ve read a lot of topics about developing a custom keyboard for iOS and it’s clear that it is impossible to build a system-wide alternative keyboard.

But I still try to understand how Emoji keyboard(the emoticons additional layer) could make it possible and it is an official app on AppStore (that means it passes Apple approval!).

Note that their keyboard, once installed, can be added in Keyboard section in Settings!

Thanks for help

Answer 1

The Emoji Icons are a stored in the private use area of unicode. They won’t look any good on a different device than an iPhone/iPad, this is Apple specific.

The app is just to enable the keyboard. You can do it yourself: Making An Emoji Enabeling App.

Have a look at The truth about iPhone Emoji, which sheds some light on the whole topic.