Describe an example from the users perspective

[dsernst]

If this system existed, how would I log into my Twitter account from my iPhone?

[taoeffect]

You should take a look at the work the blockstack & uport.me folks are doing.

But, since you asked, here's one way it could work:

If you have an existing account on twitter

1. Go to twitter
2. Link it with your blockchain ID (assuming twitter supports it)
3. From then on, sign in with your blockchain ID

If you don't have an existing account

1. Go to twitter
2. Pick a username
3. Signup with your blockchain ID

"Sign in with your blockchain ID" just means press a button on a device that sends a challenge-response message that's signed with one of your blockchain ID's private keys.

[taoeffect]

Oh, I'll leave this open. If anyone wants to submit a PR you're welcome to, but just FYI, as mentioned in the README this project is now not being maintained by me since blockstack took the lead with the profile format, and uport.me is also using that same format.