Flight planning web site

Once Upon A Time...I'd tried out a web site that did flight planning. I
don't remember many details, but I do recall that it did a decent job in
several ways that I liked, including building a "book" of the flight's
charts (so one could just turn pages rather than refolding sectionals or
such).

I also liked that it didn't require me to run a Microsoft environment
(because I don't); this was completely web based.

This was a for-pay service, BTW.

Does anyone know to what I'm referring? Does it still exist?

Thanks...
- Andrew