A brief teaser trailer for Gears Pop was shown at Microsoft's E3 2018 press conference. No details were given, but it will feature Funko versions of Gears of War characters. A mobile game is a new venture for the Gears brand and teaming up with Funko to make use of their Pop figures versions of Gears characters means that you can probably expect the game to be a bit of a departure from the typical Gears formula.
Gears Pop will be available on iPhone and Android devices in 2019.
https://www.youtube.com/watch?v=3Pf4KxbknXA
If you want to know more about this and other announcements happening at E3 then be sure to check out our E3 2018 Coverage Hub.