Process timer is simple app that helps you measure time from process start to its end. Just start your app as the first argument of timer like timer "firefox www.google.com"; when you close your firefox window, timer is going to inform you for how long your instance of firefox were running. Time is going to be presented in nanoseconds, microseconds, miliseconds and finally seconds.
From command line gcc main.c -O2 -o timer
Have fun.
