I was very skeptical about ARK when I heard of it the first few times.  I have to admit that I wasn't understanding it very well.  But its getting more and more promising overtime:

>  [...] we aim to increase the number of participants in each round, leading to more efficient cost-sharing and lower fees for all users.

And even exciting:

> Clients can share a Nostr public key (profile) for each of their VTXOs

lightning

Github release: https://arkdev.info/blog/ark-release-v0.4/