For me this app works brilliantly: it turns running errands into a sort of game or competition and makes it just a little bit more fun. At first the app is really basic but as you progress new functions become available.
The only downside is that you cannot set tasks and 'sub-tasks'. It would be so useful if you could set a bigger task such as finishing a paper, to which a certain amount of smaller tasks contribute. Also, if you're on a holiday the app is mad at you for not doing anything - but that's kind of the point of a holiday right? Would be nice if you could disable it for a few days without paying.