Allway Sync is another Free app that can by used for backups. In fact, I looked at Allway Sync years ago, but decided PureSync had the features I wanted. However, since the free version of PureSync removed some key features now reserved for its paid version, I've gone back to Allway Sync.
I do use the program AOMEI for complete system image backups, but also use Allway Sync for more frequent intermediate backups of key files. Primarily for files in my encrypted partition, which includes My Documents, My Photos, Firefox, and Thunderbird profiles. Note that I'm using default save location for My Documents and My Photos, as separately encrypting those folders in Windows User accounts, other than using EFS, can cause system issues or instability upon startup.
You can setup Allway Sync, under properties, to automatically sync based on a variety of conditions. This allows me to keep updated auto backups of both my Firefox and Thunderbird profiles for instance, containing passwords, emails, and extensions, without any intervention on my part. Basically, from one encrypted virtual drive, to a separate hard drive containing another encrypted virtual drive. So both the source files and backup are stored encrypted.
BTW, if using a sync app for Firefox or another browser, I'd recommend setting the browser to clear cache, not necessarily passwords, upon exit. This just reduces the app having to add/delete cache files to the backup file, which change after each session, and is generally not necessary to backup anyway.
Some files such as word processing docs can be auto backed up as soon as a change is detected. This is particularly useful for critical files in that you end up with a backup, without having to manually save it separately. You can also set Allway Sync to keep version backups of files, so not deleted when removed from the source.
UPDATE: I've re-discovered the reason I stopped using Allway Sync. Though it is a feature rich app, the free version will occasionally post a dialog recommending to upgrade to the paid Pro version, when it decides the number of files synced is more than that of an average user. The problem is that it apparently will not continue the scheduled backup or sync job until the dialog box is closed. This makes Allway Sync Free unreliable when you are depending on scheduled backups.
It's only happened a couple of times. But enough so, that I've decided to discontinue its use, and focus back on using the open source FreeFileSync, though not as user friendly for scheduling auto backups. In fact, relies on setting up Windows Task Scheduler to run a batch file. But it also has a separate app that monitors for any changes in a folder/file and backups/syncs after a specified delay. Which is actually what I was looking for as few free backup/sync apps have this capability.