I read the whole blog-style homepage; assuming it’s genuine, this guy sounds like a hard working compsci grad trying to make his coursework a breakout product so there’s a necessary element of monetization planning. I think it’s fine to pay for a service, rather than free but monetise the data and push ads.

The space is a massive jumble of competing ideals and desires for the replacement right now. Fluxer looks optimistically promising based on the stated desire to be as much of a reverse-engineered open source clone as possible. If that’s what the majority want - a simple drop-in replacement - then it’ll succeed.