The firefox integration is not a pocket-brand application, website, or technology. It uses pocket's public API and is open-source, mozilla-developed and -licensed code.
I thought the API used was undocumented and custom to Firefox? I don't know where exactly I found the Google groups discussion going on between various Mozilla people and the community, but this was a point made a number of times. IIRC at least one Mozilla person was working on getting clarification regarding this clause of the TOS.
