Week Calendar HD is not IOS 5 compatible. I have been trying IOS 5 since summer and Week would just not start up. It simply breaks. I hoped they'd fix it before full release. That's the whole reason why developers get early Betas. I paid good money for this app but I can understand if Apple would require for non-compatible apps to be temporarily removed until the problem is fixed.
How will you like to pay money, buy an app and it just crashes and burns? If I have any impatience right now, it would be for Week for not fixing their incompatibilities while scores other apps have done the same. But I don't have any impatience towards them. I am sure they are sweating it out whereever they are. I mean! It's a survival thing for them right now. And they have to do better than just be compatible especially now that the default Calendar app has added most of the compelling features in Week. I still need my Week HD. I miss the aggressive way it can schedule very crazy recurrent events, like "every second Thursday" ... and things like that.