I don't have a ton of features planned.
Randomisation is one I've thought of before, but ultimately rejected because it's a thing I've played with in the past and never liked. I dunno if you remember an app called Urbanspoon from back in the day. It was basically a randomized Yelp. More often than not, I didn't want to do the randomised activity, so I'd just spin it again and again and then get frustrated and go to my normal places. But maybe that's just me.
I do have a couple of other ideas, though.
One idea is to re-holler. If I say I'm going to this brewpub and that hollers out to my friends, then one of my friends could say "Yeah, I'm going here, and I'll invite my friends, too." But then you start getting into some weird network effects that might be problematic.
Another is the idea of personas or profiles. There are events where the acceptability of your friend group changes. If I'm going to a farmer's market, it's totally appropriate to have a coworker join you, but at a BBQ at my house, I'd rather not have my coworkers join. Similarly, my family can join a BBQ but I'd rather not meet them at a professional conference.
Similarly, there are some events where I think it's OK to bring a plus-one and in other circumstances absolutely not.
Another concept is that sometimes I might go to, say, ComicCon with some friends in a faraway city. Now my definition of "local" has changed, so if I holler while I'm in San Diego, my friends back home in Boulder won't be able to attend anything -- but my friends that are with me at the convention might totally want to know what's up. So having some sort of mechanism for saying "I'm not at home base, I'm somewhere else and the rules are different" might become useful.
So far I've rejected all of those for one simple reason: they increase friction. I want this to be as simple as it can possibly be to hang out with my friends. The more friction you add, the less likely people are to keep using it. At least, that's my philosophy. So I've rejected just about every other feature I can think of.