A few thoughts. 1) Get a diverse group (geo + backgrounds) to use it. 2) Invite people to use your product in person (on their laptops), 3) Measure the impact using www.survey.io – iterate and fix all the user flows.
You can start by personally emailing them and saying thanks. Doing something public without their permission isn’t cool. I send Direct Messages on Twitter, emails, all day thanking people.
Listen, don’t tell. Conduct it on their computer. Fix the issues after each test .. iterate like mad, especially when you’re small / trying to figure it out.