Please use the following steps to install the stable version of PrivacySafer Firefox Mobile add-on for Android:
1. Download a version of Firefox for Android earlier than version 43 (you can download the .apk file of an earlier Firefox version from here). If you have an existing installation of Firefox mobile on your device, please uninstall it first.
2. Install the .apk file you downloaded (with double clicking on the file).
3. Perform the following procedure for installing unsigned add-on: a.Open Firefox mobile, b. On the URL bar type: about config. c. On the search box write : xpinstall.signatures.required, d.change the setting to false (press the toggle button).
4. Open the .xpi file you downloaded for PrivacySafer (by clicking on the file, it should be installed on Firefox).
5. Navigate to extra on the website of PrivacySafer in order to set your settings. There is an option to open extra --> Firefox Mobile Default Settings and extra --> Firefox Mobile Advanced Settings.
6. When using PrivacySafer always set the Advanced settings in order to be able to use it properly. Navigate and see how PrivacySafer protects you.