Please note, I have a "Lite" premium subscription to Addy.io. It's been an easy to use, reliable service that I've been happy with, notwithstanding what I've said below.

Addy.io is overkill for simple average-users looking to combat spam by using fake/forwarding email addresses. For them, I'd recommend use Mozilla's Relay over Addy. It comes with the browser and a Mozilla account. It is very simple, meant for the common Firefox user.

It is also less powerful than Addy.

Addy.io has a fully functional free tier and is easy to use for it's most basic function of hiding your real email address. Additionally, Addy's free tier gives you ten "aliases" to Mozilla's five. (Fifty if you pay for Addy's "Lite" premium tier).

Where Addy might really shine is for power users, people who know about domains and APIs and are particularly intense about remaining completely anonymous vis-a-vis email. But only if they already know how to use all the tools Addy offers.

If that's not you, don't expect any guidance in how to use Addy's many features because the DOCUMENTATION IS INCOMPLETE and smacks of the "we'll get to that later" tone common among open source projects. What documentation exists is readable, but weakly written, full of unnecessary jargon that assumes technical knowledge the average user is unlikely to have.

That said, what's there looks like the team understands the importance of documentation---especially if they're offering a product they hope/want/expect people to pay for---as there is a rough set of categories set up in Addy's "Help Center."

If you use Addy.io, I strongly advise that you to TAKE A SCREENSHOT of each and every new API you create because you'll never see that API again if you don't. The API appears only ONCE, and that's when you create it. After that, all you can do is delete its existence.