@evan @soapdog True. I was talking about this just yesterday, if we wouldn't be better served by something wiki-like to host a software project × FEP implementation matrix instead of asking FEP authors to keep their lists updated.
That aside, in this context I'm thinking about how more implementations in the wild can motivate other implementers. My own website still isn't AP-capable (it's planned, but low priority). If I knew there were a sizable ActivityPoll user base, I'd more likely use it.