Downloading older releases and beta builds
Both cases are served by the same menu, and they point in opposite directions: an older release takes you back from the version you have, a beta takes you ahead of it.
First you need to access to your Customer Dashboard from Freemius. You can find your login details in your email.
From there:
Go to the Downloads section and look for the Download text. Click on the "dropdown" arrow icon beside it. It will open a menu with the other versions available for the product.
Downloading an older release
Click on the version you want to download. Older releases are the ones numbered below the one you are running — useful when you need to roll back.
Downloading a beta build
Beta builds are pre-releases, so they are usually newer than the current stable version, not older. Look for the [Beta] label in the same menu and click the beta version you need.