When we had Canada's 150th anniversary, there was funding—I believe it was federal funding—to sponsor bioblitzes. These are community events where people go out to try to find and photograph as many plants and animals as possible in a given period of time, like a weekend or a day or whatever, and iNaturalist is the go-to app for reporting on these.
I think that was probably very successful. Certainly there were a lot of bioblitzes that came out of that, and that's a way to engage people who otherwise might not have ever heard of a bioblitz. They might be people who like to go hiking or they're casually interested in the birds they see, but to actually get them out there with like-minded people, I think that can be a very good way to get people into it, and in fact, right now, internationally there's something called the City Nature Challenge. that iNaturalist runs on a long weekend once a year, and they see a big uptake in people who sign up for the app from that.
I think that's one way you can get to the grassroots level.