PopIn is a free, bootstrapped event app. The hook for makers: I built the entire flow around guests never needing an account, which kills the biggest drop-off point in event invites. You create an event, invite by email, text, or link, and guests RSVP in one tap. Hosts get a live guest list with going, maybe, and can't make it, recurring events, and broadcast updates. There's also a deliberately small social layer (a feed limited to people you follow, messaging, stories, badges) and Pro pages for vendors. It's a PWA, so no app store. Early access, free.