You could also try to establish a group of analysts that would meet with you (virtually or in-person) that would act as an advisory group, in exchange for seeing their product inputs considered, or possibly a period of free use of the app.

The best way to find out their motivations for signing up is to ask a bunch of them. If you approach them by saying you want to pick their brains as subject-matter experts, you might find they are interested in providing input, which is exactly what you're looking for.

You could also look for a local or online association of analysts or researchers, and see if you can give a presentation to them on what you think the top app needs are, and see what feedback you get.