> So, when I finally did post, it got one upvote, and quickly disappeared. My disappointment was significant.

We've all been there, trust me. This is actually a good way to tell if your app is needed. Float a small working version around HN and other sites, if there is little-to-no feedback then you know the market does not really need this app.

I know it sucks when you've invested countless hours into this thing, but getting no feedback is actually valuable feedback.