You dont need it.

If all you want are the emojis you dont need ANY app so dont bother downloading if you only want the emojis. The emojis are made by apple. To get emojis go to Settings>General>
Keyboard>Keyboards>Add
New Keyboard>Emoji. Go to your keyboard and press the ball shaped icon and select it.

Lex9.0 about >Emoji, v4.9