I have asked around previously. I didn't get much response. I posted a short list to my blog:

http://micheleincalifornia.blogspot.com/2015/10/bicycles-on-...

This list is not just software vendors. Some are webcomic artists. I was interested in any really tiny web operation actually making enough money to support the people running it.

I suspect the lack of response is partly due to low visibility and/or a desire to lie low. Small shops that don't want to grow into big corporations do not necessarily want excessive attention and also may not be well known enough (as a Micro ISV specifically) for other people to confidently say "Yup, this qualifies." A small shop doesn't need tons of traffic and money to support the few people working on it and may view excessive exposure as a bug, not a feature.