How does the emoji app change the keyboard

Question

How does the emoji app modify the default apple keyboard? I thought apple kept the keyboard off limits for developers...

Answer 1

Between IOS 2.2 - 5.0, the emoji keyboard was only available when you selected the Japanese keyboard and added the key 'EmojiEverywhere' to Preferences.plist.

Now anyone can turn the setting on: Setting:General:Keyboards: select 'add new keyboard' and choose 'Emoji'