You must know the basic understanding that you can not install JAR /JAD files on android. You must to convert the files be .APK files. You can use apps below to converting. This app is very useful if you don't want to root your phone.
Here is two ways to install jad/jar file :
Using Zipsigner 2 app direct on your Phone :
Use Zipsigner app to “extract” your jad/jar file to apk file. This software is the replacement for the original ZipSigner app. The original no longer receives updates
Using Android J2me Runner Converter from PC
You must follow above link to find page online converter. With this application, you can instantly port any existing J2ME [jar/jad] application into android [apk] without source code. Follow this page : J2me Converter page. This application runner will instantly convert any downloaded jad/jar files into android package on the fly when integrated with browser. You can upload your jad file to convert to apk file by online.