This app is a new market place where analysts / research providers can value their researches online directly to investment managers. But investment managers are hard to reach. I need to figure out what would be their motivations to sign up to the app.
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.
Start a group in LinkedIn and reach out to potential prospects to join the group. Don't just talk about your product with every post. Post interesting stories about your industry and even post other types of information for entertainment. I started a property management group not to sell anything, but to share and I am close to 3,000 people with pretty much no effort. If I had applied myself I could have probably had 10k.
You could also have a one page landing page (website) that seeks leads with an online submit form. These work very well and they are open 24-7.
The way you convert these leads will be with a good presentation. Try it and tweak it for the best results. You are basically an actor with a script. Get a good script and don't deviate from it unless you see that it's not producing results or even taking to long. Change it often to try new things.
One last thing to keep in mind. What works today may not work six months from now. You have to always be trying new ways to get yourself out to the market place. If you can realize that success is being able to change and grow when needed you will be the tops in your class. Most fail because they do the same thing over and over.
I have been in business 25 years this coming April and I have changed to meet the demands of my clients and customers on a regular basis. One of the best ways to find out what they want is to ask them.
If I can be of service to you let me know and give me a call. I have help many businesses, hotels and apartment complexes reach higher financial goals and give them ideas they have never thought.
It can be overwhelming sometimes, but the excitement of something finally working is well worth the effort in finding what works best for your situation. Good Luck!