Well, it is subaddressing, but has more related features on top of that. It automatically labels emails based on the address, and allows you to set some settings for that label, like mark as read, send push notifications, show in the “Aggbox” (the equivalent of the inbox), and screen new senders. That last one is important, because it means you can use labels for communicating with real people, and labels for getting email from automated senders (like your account email).

Right now, it’s a progressive web app. I’m working on a mobile app and IMAP support (so it will work with any email client). I’m also working on custom domain support, so you can bring your own domain and if you end up wanting to move somewhere else, you can keep all the same addresses you set up.