Yes it is an Amethyst fork with a Monero wallet and support for tipping

And then switching from Matrix to nostr channels and from IRC to SimpleX private messaging

If you want a more decentralized system + with strong privacy and anonymity, we should use nostr communities instead where anyone can create throaway npubs and you can access it from any nostr website, not being stuck to a single domain:

• https://satellite.earth/n/Monero/npub1kemda478drtx5at65wt8kyjrmy9l27hmp8gsgnfjr8vdgf8y46sqsw0hnv
• https://nostrudel.ninja/#/c/Monero/npub1kemda478drtx5at65wt8kyjrmy9l27hmp8gsgnfjr8vdgf8y46sqsw0hnv

It seems to be more like hiding coins in different addresses while obscuring it on chain & using some clever math to make the UX better.

You are accurate: you “hide” coins in different addresses which are only know to the receiver and the sender, I cannot paste a SP address in a block explorer and find what addresses belong to it, and what is the total balance of this BTC user. I can however send a payment to it and then have a “watch” on this entity, there is no obscuring happening on-chain so usual heuristics like when a coin is spent, to where, how much is change, etc still apply.

Which also means if they spend many SP payments together, they reveal to me & others all the addresses belonging to them and what the total balance was, you can think of it like if bitcoin users sent their BTC addresses to each other via DMs, but it removes the interactivity step from handling new addresses, while adding the scanning requirement so the receiver can also know which addresses were generated to them without having to ask senders each time

It is a good feature to have in general in my opinion, but definitely does not come any close to competing with Monero still