If you've got "more than a few people jumping to invest in your idea, who want some sort of corporate entity to exist so they can own shares of it" you've probably already made it. The scenario where that happens while it's still just an idea you're treating as a hobby seems pretty implausible.
but, you have a tiny, dedicated userbase (which you've purposefully kept small so you could personally tend the garden of your own community and work out bugs), and more than a few people jumping to invest in your idea, who want some sort of corporate entity to exist so they can own shares of it--
is it time to register as a company?