Hello. I would enjoy working on a project such as this; since I'm an empathetic person, and making others safe & comfortable makes me happy. As an organization, you're doing good work. I appreciate it.
I could make this app in Flutter, to make it accessible easily for both Android & iOS users. I would also use Material Design techniques, to make this app beautiful, and comfortable for its users. (Maybe even setting your own comforting colors, comforting stuff? I have some experience dealing with trauma, and comforting things help, integrating them in an app would help as well.)
I built multiple apps in Flutter, some small, internal apps in Android, and also did some small apps for iOS. I feel most comfortable development-wise in Flutter. Regarding front-end, that is.
I assume there needs to be a backend as well, so if you won't hire another developer to do backend work, I could also do it.