Asking here, unable to reply to the comment below.
The hard part is identifying them, and picking one where the value added by a web app is worth paying for.
As someone who doesn't have any contacts with companies (I'd assume this is true for most people here), any pointers on how to go about doing this? I tried the cold email route (even made a friend this way, we still keep in touch after two years, though we haven't met and probably never will), but I didn't succeed. I probably could have, but it made me so uncomfortable writing to total strangers :(