I think I may actually be wrong, I think some validation does happen on the phone, and the lightning routing and preimage management happens on the phone too. Similar to Phoenix Wallet.

Breez I believe is a full node, same as Zeus. This is why they are quite slow to start up.

Mutiny offloads some of its complex networking responsibilities that it cannot do within a browser and some computationally expensive tasks, but it seems to do what matters on device, so it's as good as having a node on the phone.

nostr:npub1mutnyacc9uc4t5mmxvpprwsauj5p2qxq95v4a9j0jxl8wnkfvuyque23vg where do we draw the line? Does mutiny run a node on the phone?