Source Article here.

Apple, please do not enforce such arbitrary restrictions on the design of notification center widgets that will remove useful implementation such as the notification center widget in PCalc.

These widgets are very useful in a variety of circumstances, saving the user from having to leave an app to do a simple task. Under the iOS memory management system, a user leaving an app can cause the app to need to be relaunched, and the state potentially lost upon returning. Using notification center widgets such as this calculator improves the user experience of iOS sigificantly.

Please support this petition by signing, and hopefully, Apple will listen, and allow this new functionality in iOS to be useful, instead of another shelved half-implementation, like Dashboard.