HOWTO add jar to android project on Eclipse

Create libs folder in root directory of your project place (Copy/Paste) your *.jar in it and then:
Your Project -> right click -> Properties -> Java Build Path -> Libraries -> Add JARs -> choose the jar you have just place in the libs folder - > yourjar.jar


Your new jar will reappear in the root of your project.


OR:
place (Copy/Paste) your *.jar in root directory of your project and then:
right click it -> Build Path -> Configure Build Path -> Libraries -> Add JARs -> choose the jar you have just place in the libs folder - > yourjar.jar


This is the moment at which your new JAR is converted for use on Android.