I think it is quite difficult to let complete strangers to your home without any help from technology. I don't think this app would need any rocket science, but I would guess that a simple way to verify who you are dealing with and make that public ("John Doe is joining our board game night today") and some kind of scoring system ("John Doe has wanted help x times and given help y times and on average people do not seem to think he is an asshole")
But I think the crucial point is that if you want to fight loneliness, it is difficult to do that if the lonely one is made to think that he is now getting something because he is lonely. That will instead make him feel worse. It would be much better to tell to the lonely one that hey, just you, I would need your help. (Complete amateur psychologist writing here)
Perhaps having mandatory face shots being part of the app (you can at least know what age demographic the strangers are in) as well as a blacklist (preferably hard to get on to avoid abuse). I would want to avoid a scoring system, that slips into "good person" quantification territory. For the second point I agree with your concept, but I don't have an idea for the implementation. Random matching?
Maybe some combination of real name, photo, social media accounts and trusted networking (these are the people that I have verified to being what they say they are etc.)
Scoring has its challenges, but somehow I think there should be a way to flag people that do not behave decently. Maybe just two grade scoring with wording that makes it clear that the lower grade is applicable only if the person has e.g. threatened with violence or completely disregarded what was agreed (being a bit late or politely cancelling in the last minute is not sufficient)
And for the second part, I just thought that it would be enough to get a notification on your phone that someone nearby could use some help that you can give. Not probably a perfect solution that saves every lonely soul, but if even a few, that would not be bad. And of course, maybe also some of the not so lonely ones get to receive or give some help.
Wow, you've put some good thought into this. Being able to say "I could use help taking down a tree" would be great - signing up and attending an event is one thing (meetup.com), but hard to do if you're down. But actually being needed and being able to help! THAT is powerful! Please do this. I'll help if I can.
There are a few problmes here. first one is that I have currently my hands quite full. Second is that for a successful launc, I guess a good idea is about 1%, technical MVP is another 1%, execution of everything else maybe 18% and pure dumb luck 80%. Here, even if I had time to come up with the MVP (and honestly, I am very sue that there are people reading this that would come up with the MVP in a fraction of time than it would take me), there is still the 98% left that I am really bad with.
I am open to discuss about this further, though, if there are people interested in taking a lead. (Ideally I would see this built as a open source client on top of some distributed data store and not a for-profit thing, but that probably is way too idealistic)
But I think the crucial point is that if you want to fight loneliness, it is difficult to do that if the lonely one is made to think that he is now getting something because he is lonely. That will instead make him feel worse. It would be much better to tell to the lonely one that hey, just you, I would need your help. (Complete amateur psychologist writing here)