Of all the Android apps I've tried, I'd suggest Productivity Challenge Timer:
what this app is about is challenging you to work harder and tracking your work habits.
It includes tracking of projects so you know how much time you spent working on each of your clients/books/websites/whatever - like a time sheet, but it's not meant to be an organizer or a to-do list.
You'll earn/lose ranks depending on your performance, earn achievements and track your productivity over time, so you'll know how long you worked on what and during which days of the week and hours of the day you're at your most productive.
Personally, I love the humor, love that you can name different projects and track your progress over time, love how this app turns work into a game.
Then it's Clockwork Tomato. It it's essentially a timer (offers a ton of settings, though)
has a beautiful UI, you can also use the widget it offers for quicker launch,
and can display history for all completed pomodoros, in columns for days, aligned by hour.
It also has these two great options:
- to "include unfinished pomodoros" in the log (eg. if you start a
pomodoro and press skip/stop before 25min - but at least at 60% of
it's duration) it will be proportionally be added to the log of
- Also it has the "auto-continue" option: when a timer ends, to
automatically start the following timer.
Then, it's also "Pomodoro.txt" (google it - I can't post a third link in the same post, yet).
It offers a to-do list which you can order and filter by priority.
Then you can start a task with the option for pomodoro length of 10,25 or 45 min
It also history of completed pomodoros
and can sync via Dropbox in order to backup the to-do list.
Last, there is "TimeWise: A Pomodoro Timer" (google it)
it also offers a to-do list, where you can assign pomodoro to each,
and also can display history of completed pomodoros.
I hope that in the next update it will improve, because it still has some issues.
And, for windows, it's "XorTime" (google it).
It offers a paper-like interface with a to-do list, an unplanned list, and an activity inventory
-all exactly as Pomodoro Technique instructs-
you can assign pomodoro to each,
also can dsplay history of completed pomodoros,
and can display statistics for all completed/bad pomodoros and interruptions.