General :: Time Tracking App With Parallel Timers

I need a time tracking app. There is a lot of time trackers on Google Play and I've tried a lot of them, but in every app I missed one important feature: parallel timers for different clients and jobs.

I need:

- to define my clients, to define my jobs I do for the clients, to define projects.
- to simply choose client, project and kind of job and then start the timer
- to simply start and stop MULTIPLE timers (start and stop one timer, while second timer is still running)
- to export all data in usable form (for billing my clients)

Example of what I mean:

- My job is phone support. I am sitting at home and answering phone calls. I am payed for hours, so I need to start timer and leave it running almost all day untouched (except of lunch time).

- Because I spent most of the time by waiting for calls, I simultaneously do other jobs. I write articles, compose music and do some other work for other clients. So I need to start and stop timers according to actual work - but the "phone support timer" has to be also running. When I am - for example - writing an article and someone calls me, I need to stop "writing article timer", pick up the phone and solve customer's problem. When I drop the phone, I need to start "writing article timer"... etc...

This kind of app with parallel timers I've used on my Psion PDA back in 1998, but I can't find similar app for Android phones.