Well today i came across some old xap files from the good old times when we were able to download xaps from store. So i tried to install it on my Lumia 1520 running on windows 10 mobile build 10.0.14977.1000 but the tools (windows phone app deployment tool and power tools) were not able to detect it. And they can perfectly detect my Lumia 1020 running windows phone 8.1. So i was wondering if there is a different way to do the installation as in the past, the old tools worked fine with the windows 10 mobile.