I specialise in getting your mobile app to its target audience and giving it the ranking it deserves in app store. I used to be a marketer in offline sphere, but I think e-commerce market is better now .
So my job is mobile app promotion now. I write app review, do app store keyword research, introduce some ads and use other google play store hacks (https://app-reviews.org/google-play-store-hacks/)
To promote any product it's suppoused to know it's the main characteristic, in my case I should know something about programming to understand how mobile apps work.