The nice thing is: the way they implemented this it looks like you could pretty easily write a 1passwordish mac client as an interface to the system infrastructure. I say "1passwordish" because one of the tedious part of a program like that is the browser parsing to handle all the weird authentication cases devs write.
Unfortunately I'm not an ios dev and wonder if it might even be possible to do the same on ios? I believe there is an API so you can write a password manager (1password et al use that) but can you get to the secure system services?
Edit: I now see who wrote this blog post. Were it straightforward on ios he probably would have said so.
I am not an expert macOS/iOS developer but I unsuccessfully played around with the API a couple of times.
You can’t access passwords stored by another app (app identifiers appeared to be globally unique, e.g. com.apple.Safari). There was an additional hurdle to access/store items in the iCloud keychain, though I forget what exactly.
Unfortunately I'm not an ios dev and wonder if it might even be possible to do the same on ios? I believe there is an API so you can write a password manager (1password et al use that) but can you get to the secure system services?
Edit: I now see who wrote this blog post. Were it straightforward on ios he probably would have said so.