Essential, and great support If you have DEVONThink on more than one Mac (e.g. desktop and laptop) this is an indespensible utility to keep them in sync. Allows you to add records to either database and then bring the together in ways not possible with apps like Chronosync (which I also own)... For a piece of software with an $11 tag I can't compliment the service or the product enough. Fantastic.
–Eric Boehnisch-Volkmann (President, Corporate Communications), DEVONtechnologies LLC
We have intentionally not included [a sync] feature [in DEVONThink] as it is complex and error-prone. However, you could have a look at DevonSync made by Wooden Brain Concepts.