[nols]

Here are two app marketplaces:

https://flippa.com/

https://www.sideprojectors.com/project/home

[kiberstranier]

We tried some other marketplaces, but the quality of apps there is not very high. We would prefer an app that solves a real problem.

[nols]

So you're looking for high quality abandoned apps? I think you're looking for a needle in a haystack.