single-word-requests
I am a programmer, but not professionally. I do have apps on the Google Play Store, but it's mainly a hobby (and I don't earn much at all; about a few cents a month).
I'm sure there must be a word for this type of job (i.e. a non-professional job done mainly as a hobby), but I don't know what it is.
In Canada you're likely to hear these called "snow pants". Most children's snowsuits come with pants and a jacket and the pants cover the stomach and back like overalls, and have suspender straps to keep them up. There are other models, which do not cover as much, and instead are meant to be worn over regular pants.
Example snow pants from Google Image Search for "snow pants":
Dabbler: a person who follows a pursuit without attaining proficiency or professional status.
Best Answer
I think hobby itself would do just fine. Hobbyists work at their craft when it’s fun and convenient, but don’t make the necessary commitment needed to get to the professional level.
"Selling apps on Play Store is my hobby".
So you may be a "hobbyist programmer ". Some people actually hate that name.
What you're describing may also be a sideline career.
"He founded the fast-food company as a sideline to his petrol station"