Wired: When Mailbox sold itself to Dropbox for a reported $100 million or so this March, the month-old iPhone app wasn’t even available to the public. People could download the email organizer, but using it required joining a mailing list that stretched to nearly 800,000 names at one point.
For months, Dropbox users were waiting, and finally, they can download a beta of the desktop app that operates natively on Apple’s Arm-based processors. Users
However, there's a catch: the app is invite-only for now. While the general public can download and install it onto their devices, no one can use it without being granted access (presumably a beta key of some kind).
The good news is that folks who had more than three devices attached to their account before March 2019 will be spared from the three-device limit.