I did something like this ages ago and attracted some hackers that in turn attracted the FBI to my house. I suppose in hind-sight I should have made them sign legal documents and had them notarized but I still would have had to deal with the feds. It didn't end with that. They also pissed off all the locals and the local police offered to drive them far out of the county and just leave them somewhere but I ended up paying to put them up in a hotel and paid to store their stuff in a storage at the advice of my lawyer. I guess all I am suggesting is to be careful.

Sounds like it would attract a bunch of really strange people. I know as an adult I wouldn't want to live with a bunch of strangers so I can work on my app.

Think about it for a second, for one you're excluding anyone who has a family. This means that you're looking at inexperienced people, and furthermore they'd have to not put too much value on their own company. Why would I give up any of my equity for the equivalent of at most $4,500 in rent.

London is also a really bad choice for this type of thing due to cost of living. My plain right now is to go to a cheap Asian or Latin American country where I can live off 2k a month or so. Then work solo on my ideas and prototypes.

Probably not gonna turn into anything though.