You may find it confusing that there are apparently two versions of Moom for sale: Moom Classic (a.k.a. Moom 3) and Moom (no modifiers). Here's the story behind the two Mooms…

When Moom launched, way back in 2011, it was available in both the App Store and directly from us. This was true for many years, up through all of Moom 3's timeline. However, during this time, the App Store rules changed, and apps in the App Store had to be sandboxed. Apps that were in the store at the time this rule was applied were allowed to remain in the store, as long as there were no major changes in functionality, even if they weren't sandboxed.

Moom uses something called the Accessibility API to move and size windows in other applications—this is how most apps that allow you to manipulate other apps' windows do what they do, so it's not just a Moom thing. The problem is that the specific pieces of the Accessibility API Moom needs to use cannot be sandboxed, so Moom cannot be sandboxed.

That limitation presented a problem when we were ready to release Moom 4: It could not be in the App Store, because it could not be sandboxed. And we couldn't just modify Moom 3 to have Moom 4's features, because those major changes would also trigger the "must be sandboxed" clause for existing apps. The App Store is a popular way for Mac users to find and install apps, and we wanted to be there. But we couldn't be there with Moom 4.

This quandary led to the App Store presence of one Moom Classic, which is simply Moom 3 renamed. It remains in the App Store, as it's a perfectly functional app and works very well, as it has for all 15+ years of its existence. New users can find and use it, and if they're happy with its features, they have a great solution for just $6.99.

Outside of the App Store, Moom (no modifiers) is our newest release, and version 4 has a ton of new features. Moom is only sold directly from our web site—and this will be true for all future Moom releases, unless/until Apple changes the rules to allow such apps to be sandboxed. If that were to happen, we would return Moom (no modifiers) to the App Store.

And what about those App Store Moom Classic buyers who discover the newer Moom outside of the App Store—will they have wasted their $6.99? Not at all, because these users are eligible for Moom's $8 upgrade pricing, bringing their total cost to purchase Moom into line with those who buy it directly from us—$15 total ($14.99, actually, for App Store upgraders).

That's a tale of two Mooms. One exists inside the App Store, one exists outside the App Store, but both will easily handle your window management needs.