See Atlassian Marketplace for the download.
The source code has also been migrated to the excellet Bitbucket service. Sources can be found at https://bitbucket.org/wimdeblauwe/jdvp and the documentation at the embedded wiki: https://bitbucket.org/wimdeblauwe/jdvp/wiki/Home
This version would not have been possible without the people that donated on GoFundMe so a big thank you to them all!
PS: One breaking change is that linking of multiple custom fields is no longer supported. It never worked really well anyway and I had to remove it to support the inline editing capabilities of JIRA 5.1.