The CityCab (with restrictions), the ColorBlinder and the PopUp Hell are made free!
PopUp Hell is now free, without any ads, IAPs, or paywalls. I made the very same thing with ColorBlinder, and a region-locked application.
Also, from now, ColorBlinder is free on iOS too.
On CityCab’s part, it’s a bit more complex.
On the mobile platforms (Android, iOS), I’ll give it free, with ads, and you can get rid of ads with a one-dollar IAP. On the desktop platforms, I’ll sell it for one dollar/euro, instead of the 5-dollar price. GOG has denied my request, so you will only be able to get it on Steam. You can vote for it to release on Steam Greenlight.
Have a happy new year!