What the prog does is to remember logins, form details and passwords for sites, it will also generate a random password if required and remember that for future visits to sites. It resets itself on reboot or after a period of non use and requires a user password to gain access to the stored details. If the software were uninstalled you would lose access to the stored sites unless you had a seperate list of the logins, passwords etc used, then you could log in as normal. It would not give someone direct access to those site unless they were able to hack the software which I would hope is fairly well protected.
Whether it is worth the money I'm not sure, but it does save a bit of typing and chasing forgotten details!