I looked into this more. I’m not sure if it’s easily possible to build a native signer app in iOS. There doesn’t seem to be the equivalent of Android Intents or bidirectional cross-app communication. Maybe it’s possible to build something janky with custom URIs. 

 Damn, i was hoping someone was working on this but sucks to here it would be janky. Still curious to see what a janky signer would be like though 

 I’m working on it. I thought up a different way.