Beta and developer versions of YajHFC can be found at http://download.yajhfc.de/betas/
Compared to the release version the betas usually contain additional features and/or bug fixes, but may be less stable than the release (and translations often are incomplete).
The betas are updated in irregular intervals without special notice (usually whenever some notable new feature or bug fix has been implemented).
Please note that the beta versions are not necessarily newer than the current release version, especially shortly after a release.