When the app opens look at the bottom right for the little shirt icon that says "Products". Click on that.
That opens a page with lots of retailers and collections. You click on each collection and scroll to the bottom (past their products). Many of these will have envelopes that say "Tap for a Surprise". These are usually worth 1 Kick, although I've had a few worth 3 or 5. After you have opened it, it will say "Enjoy".
If you look carefully you can see that many of the collections have a white border around them. When you open these they swipe right/left and they never have a bonus envelope. Only the collections that scroll up/down have bonuses on them, and not all of them do.
They add collections all the time, so it's worth it to check those products a few times a week.