检测哪个应用程序（Web，移动或触摸浏览器）正在加载网页？

If you look at the image, there are shared web pages between the 3 applications, Web, Mobile and Touch Browser. I need to report the web pages uniquely per application. So if web page A is loaded, it will need to load different JS libraries for each type of application. Currently a JS bootstrap loader file handles the logic to load the proper JS libraries but that is a 1-to-1 relationship. I now need a way to determine which application is loading the web page and load the appropriate libraries (DTM libraries but irrelevant). The solution would have to reside in the JS bootstrap loader file logic. I’m looking into using the navigator object to sniff out which type of application is requesting the web page but not sure how feasible that is? Maybe feature detection is another way but not sure how/if this would work with the applications? Any ideas?If you look at the image, there are shared web