Android app to track parallel activities over the day with a single click

I’m looking for an Android app to track how I spend my time.

I’d like to define activities (such as working, sports, commuting, …) and want to be able to track how much time I spend doing each of these activities with one (or very few) clicks. That is, when I stop working and leave the office for home, I want to be able to click “Stop work” and “Start commute”, and the app then counts the time until I click “Stop commute”.

I also need the app to be able to track parallel activities (like working on the train while I commute).

Which apps do this easily?

It would be great if I could export the data, but that’s no necessity. The app (and data collection) must work without network connection, i.e. the data must be stored locally, on my smartphone.

I don’t have an Android phone so I’m sorry I can’t help with this question. Many QS people have used Toggl and Harvest; I’m curious about parallel tracing, whether these work on those apps…

Thank you, Gary. Toggl support told me that “you are not able to have two running timers at the same time.”
From this overview of time tacking apps, I have now chosen Zeiterfassung, a free, open source Android time tracking app with exactly the functionality that I need – and no more.