Microsoft Silverlight is only for Windows and Mac OSX. https://www.microsoft.com/getsilverlight/Get-Started/Install/Default There is no Firefox 52 ESR for Android as that is desktop Firefox only. Also the only Plugin that Android Firefox really made use of was Flash Player however Adobe stopped making the Android version back on September 10 2013. Mozilla later stopped support of it as of Firefox 56.0 (Sept 2017) and later.