MojiLaLa Unlimited is an iMessage App, and it is on your iMessage section, not the home screen. Apple designs it. Unfortunately, you had a hard time to find the app because of Apple, not us.
To use MojiLaLa Unlimited, you can follow these simple steps
1) Open or start a conversation in iMessage
2) Tap the “App” button to the left of the message field.
3) Tap the button on the bottom left of the screen to view your installed iMessage apps.
3 a) If you don't see the app in iMessage apps it's because you "automatically add iMessage Apps" is not enabled. Please tap the big "Plus" icon to the store sign.
3 b) Tap the "Manage" app section located top right.
3 c) Tap the On/Off toggle to enable the app.
4) Tap 20000 Stickers icon to open.
If you can reconsider your review, we will be glad that.