It keeps your working lists synchronous on the desktop personal computers and android mobile phones. There are no sub-tasks or advanced features that make it useful for planning bigger projects or handling regular tasks. The WhatzAct really shows you "important", "time limited", and "general", so you don't get overwhelmed by dates and times. It is easy to use and a very lightweight app.
By the way, there are extensible features available on desktop version. You may feel free to access it across desktop browsers with url whatzAct.com / whatzToDo.com.