the only thing you can do is move on. maybe keep a mental note about the company/developer behind it and if they launch something else in the future keep that in mind

multiple reasons for moving on. could be (as you correctly said in your op) that no money flows and if the dev doesn't use it personally anymore, he has no incentive to develop it further or fix bugs. maybe just part of life, something that interested me years ago, might not be that interesting to me anymore today