Superhuman

The most controversial productivity app on this list: an email client that costs $30/month and has a waitlist. Superhuman's value proposition is speed — every action is sub-100ms, keyboard shortcuts for everything, and an AI that writes, summarizes, and triages email. The onboarding includes a mandatory 30-minute video call where a human teaches you how to use the product. It sounds insane, and yet the NPS score is 58 (for reference, iPhone is 47). Users report saving 4+ hours per week on email. Superhuman raised $633 million and is used by founders, VCs, and executives who value their time at > $30/month.