In brief: There's never been a more lucrative time to be an app developer - or at least, that's what one could surmise based on the latest data from mobile app research firm Sensor Tower. And to think, this entire industry didn't even exist just over a decade ago. Incredible.

The market intelligence and insights outfit estimates that consumers worldwide spent $21.9 billion on apps across the App Store and Google Play in the third quarter. That's an increase of 22.9 percent compared to the $17.9 billion spent on mobile apps during the same period a year ago.

Apple's App Store brought in an estimated $14.2 billion in gross app revenue during the three-month period, up from $11.6 billion a year earlier. Google Play, meanwhile, was responsible for an estimated $7.7 billion in revenue, a 24 percent increase over the $6.2 billion generated during the same period in 2018.

While Apple may have generated more revenue, Google was the clear leader in total app downloads with an estimated 21.6 billion downloads in Q3. In comparison, first time app installs on iOS checked in at right around eight billion.

Sensor Tower also provides some interesting insight into app popularity. Excluding games, the top revenue-generating app across all stores was Tinder followed by Netflix, YouTube and iQIYI, in that order. In terms of sheer downloads, WhatsApp led the pack. TikTok, Messenger, Facebook and Instagram rounded out the top five. That's right, Facebook owns four of the five most-downloaded apps.

For those curious, the top grossing game was PUBG Mobile followed by Honor of Kings and Fate / Grand Order.

Masthead credit: Apps by iQoncept