The 2nd alpha version is available for people to test and play with:
The biggest changes are that PHP 7.1 is required now. There are tons of bug fixes and extra features, which are documented in the changelog, and some things to make things easier, based on feedback. Bugs, etc, should posted in the issue tracker on Github.
The next release will be a beta version, with finances working, and hopefully finalized all features for a major release. No, I don't have a timeline
*NOTE* ATM, there are no ACARS compatible. The API won't be changing much, so see the docs if you're wanting to develop your own ACARS application, or to update yours to add compatibility: http://docs.phpvms.net/developers/acars