I believe it is (or was at some point) an option for the iPhone, and a few other phones.
I've always found it silly, because in my experience, "Open network" never means "just connect and it will work". At best, you have to agree to a few terms of service (which requires action from me), at worst, you have to authenticate and/or pay or there is another security measure preventing access (MAC whitelist, etc).
Definitely not on the iPhone. The closes it comes is automatically displaying a list of available networks if there are any and you aren't connected to wifi, and letting you connect to one if you explicitly ask for it.
I rather doubt that, as it would be a big security problem. If phones auto-connected to open APs, anybody could run a rogue one and collect passwords, sessions, etc.
I might be wrong, though, or it might have been something that's since been rectified. I use a "feature" phone now, so I don't actually know what the most current phones do.
> in my experience, "Open network" never means "just connect and it will work". At best, you have to agree to a few terms of service
Nope, an office/research park around here has one, in the central building with restaurants and shops, that you just pick from the WiFi list and are on with no fuss.
I've seen McDonalds' networks like that, too (though some have user/pass to fill in a login screen, but with keys printed in the the same screen). Depends on the setup supplier, I guess.
I've always found it silly, because in my experience, "Open network" never means "just connect and it will work". At best, you have to agree to a few terms of service (which requires action from me), at worst, you have to authenticate and/or pay or there is another security measure preventing access (MAC whitelist, etc).