https://conservationhub.nz/ - Very likely not applicable to anyone here because it's a very specific target market but I've been working on a platform that helps conservation groups in New Zealand record field data and work with local volunteers.
A lot of conservation groups in New Zealand have a similar problem where they need to record their data on-site for bird monitoring, trapping, etc to get funding. Some went and built their own apps to achieve this, but I noticed the groups that did ending up spending tens of thousands building essentially the same thing with minor differences in the data captured. For a while I helped groups get set up on a low budget with existing tools but none were really customizable or intuitive enough for volunteers recording their data and admins managing that, so we ended up creating a web/mobile app for it instead.