Toggl – Free.
For Android, iPhone, Linux, MAC, PC
Toggl is a productivity tool right in your hands. It consists of a multi-featured timer, a detailed calendar and the ability to be integrated into almost any computer system. Some users have had problems with the automatic saving feature. They also report that it is easy to accidentally change the times entered into the app.
However, those singing the praises of Toggl are much louder than those who are not. This app is especially helpful for users who bill by the hour or need to keep track of their time in small increments. Everyone from lawyers to plumbers can make a note about who should be billed for each segment of time throughout the day, or how long they worked on each specific project. Stats can then be filtered by project, time, client or task, giving users the ability to truly track the time used efficiently.