There is a German application on the iTunes store with over 750 tipps around Mac. Take a look and enjoy it. We worked on it for over a year, got lots of feedback from beta testers, several design changes and a total rewrite in the middle, but now it is a perfect little tool to lookup for help if your Mac is in trouble.
Why I show this application here? Well, because I am the developer who created this application for the Macwelt team.
PS: And over time they will add more tips. Every time you press the load button (the round arrow), the server is asked for new tips.