Warning: OOHanzi 0.6 does not seem to be installable on Mac OS X. I have tried this week to install it on a Mac without success. I do not know whether previous versions would work or not.
OOHanzi 0.6 has been released.
Of all the releases of OOHanzi so far this is the one which has required the most work and which contains the most substantial changes. There are significant visible improvements but the bulk of the work happened under the hood and is invisible to regular users.