Adobe Flash has been on the chopping block for ages but it doesn’t seem to want to die. Mozilla is taking a step towards removing it from all its properties with its latest announcement. Firefox 56 for Android will no longer support Adobe’s multimedia plugin. This means, Firefox on Google’s mobile OS will require Android 4.1 or higher to work, which is the Android version. You might not notice much of a difference here since most sites have dropped support for Flash but if you still need to use it, Dolphin browser works.
Source: Android Authority