How to download and start firefox app ?

Hi 284gedamu, You can download Firefox from Mozilla's official website: https://www.mozilla.org/firefox/new/ Select Download Firefox, then open the downloaded file and follow the installation instructions for your device. To update Firefox, open the menu and select Help > About Firefox. Firefox will check for updates automatically and download any available updates. You may need to restart Firefox to finish installing one. Could you let us know which device you're using (Windows, Mac, Linux, Android or iPhone)? I can then give you the specific installation and update instructions for your device.