Try one of these articles:
- Private Browsing on Firefox for Android Private Browsing on your mobile device is great for viewing websites incognito - without saving information about the sites you visit.
- Clear your browsing history and other personal data on Firefox for Android Firefox for Android makes it easy for you to delete your browsing information. You can even automatically delete your data every time you quit Firefox.
- How does Firefox for Android use the permissions it requests? When installing Firefox for Android you may be asked to grant a number of permissions. This article explains what these permissions mean and how they are used.
- Why can't I sync my passwords? This article explains why the sync passwords option is greyed out.