SlamAd was a ‘whatsApp’ look-alike that allowed people equipped with the app on both sides of the chat to communicate. It added in ad-mob adds to the feed (OK, I have to say this was a silly idea for the company, but, hey, I learned a lot about the ad eco-system, and they paid me well)

Here is the SlamAd website: https://slamad.com. The app is no longer in the store.