Transfer the APK to your phone via USB or SD card and open it to install. 🌐 Recommended Alternative: Mobile Web
To get Facebook on Android 2.1, you cannot use the current version. You must install a "legacy" version of the app—an older build designed for the hardware and software limits of 2010.
You need Facebook for Android or older. These were the last builds for Android 2.1.
Go to Settings > Applications and check the box for Unknown Sources . This allows you to install apps from outside the Play Store.
