Founder here. All ugly crying aside, I built an automated payment reminder tool for freelancers and small business, called Dun, which started as a Windows desktop app I built for myself because I was tired of writing awkward "just checking in on that invoice" emails. I also convinced my old boss to use it (for free) and he liked it. After that, got a handful of downloads, then made the scary call to rebuild the whole thing as a web SaaS with Stripe/QuickBooks/Xero integrations. This is...