1. First, want to say kudos for building this app and putting it out there. It takes works and guts to do that.
2. "Overly promotional" submissions come off as spammy to me. Some of this is likely cultural, but things like "It definitely restored my faith in humanity" and "We are on a mission to end loneliness that is gripping our world today" are not likely to be that well received on a site like HN for an app that basically lets strangers leave voice clips. To be quite frank, I went and visited your site, and if it "restored your faith in humanity", perhaps your faith wasn't much in question to begin with.
3. Refrain from friends/colleagues leaving inauthentic comments. I don't know who "de4n_whit3" is, but the tone of his comment and his post history leads me to disregard it as BS.
Don't mean to be overly critical, but another commenter mentioned, "Agreed, the site would benefit from clearly answering, "what is this and why should I care?"", and you should try to better answer that.