tl;dr - it finds the best offers across New Eden
Step 1 | Copy & Paste
Use Ctrl+C to copy a list of items to your clipboard. This can be from EVE Online's asset window or even third-party tools. Then, use Ctrl+V to paste it into the panel on the left.
Step 2 | Select Locations
Choose where you want to source items from. It can be from stations or private structures across Highsec, Lowsec, and Nullsec.
Step 3 | Review & Adjust
A sourcing plan is generated with the best offers, letting you compare savings against Jita Sell prices. If you're not satisfied, adjust the selected locations and run it again.
Step 4 | Purchase in EVE
Click the convenient Multibuy button to copy your shopping list to clipboard, then import it into EVE to complete your purchases in each location.