People are working on dedicated native mobile signer apps as we speak.

nostr:npub1w4uswmv6lu9yel005l3qgheysmr7tk9uvwluddznju3nuxalevvs2d0jr5 just released NIP-46 support on Amber, an Android signer.
nostr:note17dlrejdnn878zllmwjajzun3wldwsxdkqht8dzw4dusarvee96vqq3e3vw

nostr:npub108pv4cg5ag52nq082kd5leu9ffrn2gdg6g4xdwatn73y36uzplmq9uyev6 and nostr:npub1r0rs5q2gk0e3dk3nlc7gnu378ec6cnlenqp8a3cjhyzu6f8k5sgs4sq9ac  also are working on this.

I have iOS on my aspirational backlog, but I’m pretty backlogged.