I clicked through to your site and played with it a bit. Nice idea, and well executed! Then I hit back to come back to HN... seventeen clicks later, I’m back. Might be nice to update the URL without adding a history entry.
Ha yeah, very good point. I thought it was neat to have the entire state of the app in the URL and use the back button to demonstrate that, but yes, I should probably be replacing history instead of pushing.
Suggestion: Push once after every complete phone, but replace after an intermediate state. That way the back button goes through a list of complete combinations you tried, without forcing you to walk back individual steps.
