It’s a very different approach based on Cashu(custodial ecash tokens). Upside near perfect privacy and zero fees if remaining in ecash. They can receive lightning zaps while you’re offline then you can redeem and withdraw at normal-ish lightning fees when you come online. Still beta, but an extremely exciting option to explore. Ideal for small amounts as a trade off to custodial risk(which is only temporary if you withdraw when you come online).