Yeah Alby is a good tipping app for sats as well, got that set up on our websites. I do have Wallet of Satoshi too so might start using that a bit more. I like that it allows LNURL, Muun doesn't offer that yet but I guess that's part of the complication of being a non-custodial lightning wallet.
I think WoS is a 0.15% fee if I remember from my calculations of using it last month which is next to nothing to send but I don't have a direct channel to it