If your Lumia 720 still feels sluggish, consider a (Settings > About > Reset your phone) – but back up your data first.
Use the browser version ( m.facebook.com ) for the best possible experience on your Lumia 720. download facebook app for nokia lumia 720
– You could search for an archived Facebook .xap file (for Windows Phone 8.1) and sideload it using a PC with Windows Phone Developer Tools. This requires enabling developer mode and is not recommended for security reasons, as the app is outdated and may not work. If your Lumia 720 still feels sluggish, consider