There are paid licenses for the standalone chrome app (not the extension) that let you do extra things like pre/post JS processing on requests. I think the licenses are also tied to their new sync feature which would let you sync a collection of requests (say all your API requests) across your team.
Oh, nice. I couldn't make heads or tails of their website. Seems like a lot of potential there, tho, for sure.
Postman is the only Chrome app, I have spent money on. Personally I did not find enough reasons to buy anything else in the Webstore.