web based is good, if you can code it in this way it will be better, but it still need trust, if we need to invest
I get that.
So what do you need from me in order to gain your trust?
I can share how I built the program and what algorithm it uses to calculate its recommendation. But I can't give away the source code in order to protect the people who opted in with their emails. If someone finds an vulnerability and exposes their emails, then they will loose their trust in my service.
if it is web based, i don't think it need the source anymore, if there is no exe, to download it is safer, still the website need to have the green lock at least
and if it need to invest, it need an escrow that hold the funds, maybe a member of this forum