CallTracker(BETA) is the program for cellphones with Android platform that helps its users track their calls duration, identify interlocutors, save or ignore their conversations for further invoicing, and store this information automatically on server to customers or projects. The application also enables its users to immediately view call reports for each client, which makes it easy to track and bill the quantity of time used for each client over a period of time. This application might be also interesting for companies dealing with billing their employees for calls - for example consulting firms.
User Guide (PDF document): http://android.demo.eleks.com:8080/web/docs/callTrackerGuide.pdf