If you look at the chart within the post, the last column shows daily revenue (in-app purchases). The advertisement revenue or offline revenue (e.g. selling of the posters made with those photo apps) are not included in the stats.

So, of course, Instagram does not have in-app purchases. And the Pic Stitch makes $824 per day (annualised to $300K). So the question is: is the app business about in-app monetisation, which works rather well for the gaming companies. Just use free AppInTop Spy service to look the revenue of gaming companies in the US (register free, press SPY icon on the top left hand side of the dashboard). Some make over $100,000 per day. But then the cost for the prime spots and the battle against King.com and Supercell costs much much more.