TimeTrack is a tiny application that sits on your status bar and logs the amount of time you spend in other applications. At any time, you can analyse the report for each day or a whole month.
You can install this application from Mac App Store. The application does not really have its own interface except for the report window. The whole program resides in the status bar in the form of an icon. By clicking on that icon you can access its menu, which isn't much either. The only options are: follow the program on Facebook and Twitter, visit the developer's website, get the Pro version of the program, quit and view the report. There is one line that tells you how much active time the program has logged today.
My first 5 minutes with the program were the most confusing minutes of my life. The report was empty, despite the fact that I was using TimeTrack at that time. Only when I double clicked the report, something has happened and it populated the info. I've spent a lot more time than was reflected by the program. I doubt those timings were correct.
Will I be using this application - I do not think so. First of all, I do not trust its judgement as in to how long I used an application and how long I was "using" an application for while talking on the phone: moving your mouse around so your computer won't fall asleep or you are just bored does not count as active application usage, at least in MHO. Secondly, can't tweak anything and there are no preferences, which is very suspicious.