Get it here.
Catching the leading edge of June, here's a new beta build of MacJournal. There are some more performance improvements in this build, particularly with smart journals. There are also several changes to support sandboxing, which is a required change for the Mac App Store. Sandboxing isn't enabled for these builds so those changes won't be obvious, but it's important to make sure there are no regressions the things that you use normally.
Please let me know of any issues using the Report A Bug item in the Help menu.