What does the ID-ALL Multi-Device plugin do?

It allows one ID-ALL license to be shared across multiple workstations on a network, so a team can use the same software environment instead of buying a separate license for every computer.

Which ID-ALL edition do I need for the Multi-Device plugin?

The plugin is edition-matched. It is commonly paired with the Standard edition, with versions available for higher editions. Contact Groove Badges to match it to your exact edition and number of devices.