The most important Android libraries do not come in jars because it is impossible to package Android library projects (projects that define stylable views, provide resources, etc.) in them. Just as an example, one of the most important libs for a modern application is ActionBarSherlock (http://actionbarsherlock.com/).

But there is a maven dependency available. I haven't used this, but what exactly is the problem when you can even use maven to load the file?

And do you know more libs are important? Please post them all to give me a possiblitiy to analyze them all.