I've been thinking about the huge potential of VR to help overcome the fear of flying for years, no joke. Glad to see someone has taken up the task! Good luck to you!
Another major marketing platform is becoming a sponsor of height-based sports, such as rock-climbing and paragliding competitions, or their respective national organizations (such as USHPA).
Hell, some organizations like USHPA may even want to partner with you instead of necessarily you becoming a sponsor. A lot of these organizations could bolster their memberships using new methods of outreach with your help. USHPA is one of the many organizations that I can think of that has a hard time getting peoples' new interest because people think of hang gliding and paragliding as "crazy". Most people, when asked why they don't want to do it, have fear of flight or heights as the main reason.
In short, look to the industries that would benefit from people overcoming their fears. Partner with them, sponsor them, whatever. Create outreach material with them, such as brochures or videos about their sport or niche, and have a plug for your software. Offer a free x-month subscription to your VR app with all new organization memberships. Or do it the other way around: getting a subscription or purchase to your VR app automatically gets you X% discount with partnered trainers in multiple sports: paragliding, hang gliding, sky-diving, GA, etc. Have partnerships with trainers where you send referrals to each other. Use marketing terms like "Always wanted to try X but were always too afraid? Start living life!" I could see that being a successful Facebook or Instagram ad.
I just recalled I wrote an article[0] about my vision of the future in which I mentioned using VR for overcoming fears. If you ever want to chat feel free to reach out to me via the contact details there. Good luck!
[0] https://medium.com/@eblanshey/the-world-is-undergoing-massiv...