I use Wallet of Satoshi for small transactions and the highest fee I've been ever charged was 11 sat for a 100000 sat transaction. I also use Phoenix and Electron on my mobile phones, both non custodial.

As for the computers, I use Electron and Alby as a browser extension, which I also use for signing Nostr events on the clients I use on the browser.

I recommend all of them and, of course to get rid of Muun!