FWIW, I've been using the nPub.cash/cashu.me combo for quite a while, and they're awesome! But, I recently started test-driving minibits - newly available on iOS app store - and it's even smoother. My 2 sats: especially if you're considering using the minibits mint, you may as well also just use the minibits app - the fewer potential sources of failure, the better.