With PurpleRails, you will rarely be typing your password once you successfully login. It works kinda like Gmail/Facebook etc: you remain logged in for months at a time.
This page explains why password saving doesn't work yet: https://www.purplerails.com/blog/saving-passwords-why-we-hav...
I'll see if I can do something fancier than what I do now to allow saved passwords to work. I suspect that using a Javascript-based AJAX authentication system instead of a plain-old HTML form, I can achieve the privacy goals as well as ease of use.
I hope you will hang in there and use the current version until I figure out a way to fix this. Thanks!