Password managers already do that, they just check for password type field and the site.
Keepass does that pretty sure all the others also do.
But again what problem are you trying to solve? using password managers is easy as pie today including automating signup and generating passwords, most people do not use them.
I started using LastPass just the other day because the recent news made me nervous.
It's NOT easy. The interfaces are clunky. I have to pay to get some basic features like browser plugin. There's a lot of false positives (it suggests me sometimes to save a password even if the field is not for passwords.) Generating secure passwords is hard because some sites validate length and charset only serverside and the poor manager has the invalid password already saved. Some sites play tricks to discourage pasting passwords. More than once I was unable to log in LastPass's online vault because of an "temporary error".
All in all, it was horrible, ergonomy-wise. I don't wonder at all why people aren't using them.
You're totally right. I use 1password, love it, couldn't live without it, but forgot how unintuitive and tricky it is, until I helped my wife get setup on it.
It took a while just to get up and running with the app/browser plugin/her own account, and now it's going to take a while for it to be part of her regular workflow.
The very first login I gave her (online banking) had such a bad interface 1Password couldn't auto-login.
So the next lesson was "how to work around bad website UIs, using a variety of non-intuitive menus and keyboard shortcuts".
We both use Dropbox to sync our vaults, so then I was talking to her about 2FA (pro/cons for text vs. Google Authenticator app), off-line recovery codes, an appropriate 1pass master password, etc.
There's no way she'd happen across a PW manager and love it. She's using it only because I want her to have access to all our online financials, all of which have long randomly-generated passwords.
I wish you luck! FWIW, I've found 1Password to be consistently better than LastPass.
I'm using lastpass and I haven't had to pay for the browser plugin.
I've been using lastpass for the past year or so, and I've had no real issues with it ergonomics-wise. I can't even think of any sites off the top of my head that have given false positives.
It does seem painfully slow and unresponsive sometimes though, which isn't ideal. It's slow enough to disrupt my flow more than just typing in the same password for every website.
I could use the plugin for a trial period, but now it says that I have to be a premium member? Maybe it's because I also installed the app to my smartphone, thus my smartphone become the one device I can use the free version with?
Who wants to be helping every relative set them up and adding to the unpaid support load? So they get mentioned in passing and then people think "Yes, I should do that" and never bother.
A lot of my password usage now is for apps, not web. I still know of no good way to do this with a password manager other than lots of copying and pasting, which is even more cumbersome on a phone than on a PC. I favor the apps that allow me to use TouchID.
Keepass does that pretty sure all the others also do.
But again what problem are you trying to solve? using password managers is easy as pie today including automating signup and generating passwords, most people do not use them.