Just Remember one Master Password to generate Different Passwords for Different Sites.
We do NOT store any password any where.
Any form in any site having a password field will have an extra input field called master password.
You can enter your master password there, while entering itself a password is generated and pasted to your original password field in form.
The { site name + your master password } is hashed by the popular hashing algorithm (used in banks) to get the new password.
Hashing some string will give the same random sequence of characters as output when you give the same input.
We do NOT store your master password in cloud or anywhere in computer, which is obviously the most secured, every computation is done within browser.
If you are the first time user for the extension, you will need to change the password in sites where you already have an account.