
Apple is forcing popular iOS calculator app PCalc to remove its Notification Center widget, which allows users to access calculator functions directly from the "Today" view of the Notification Center. According to Apple, widgets on iOS are not allowed to perform any calculations.
Apple's sudden decision to disallow PCalc's previously approved widget is somewhat surprising as the app is featured in multiple places in the App Store, including a section called "Extend Your Apps" featuring apps with unique widgets, and "Great Apps and Games for iOS 8," which also features a selection of Notification Center widgets.
Apple has told me that Notification Center widgets on iOS cannot perform any calculations, and the current PCalc widget must be removed. - James Thomson (@jamesthomson) October 29, 2014

Apple's App Extension guidelines do clearly state that Notification Center widgets should have a "simple, streamlined UI," a limited number of interactive items, and specifies that a widget is "not a mini version" of an app, but it does not appear to expressly disallow calculations. There's also a Pcalc app for OS X Yosemite that brings similar functionality to the desktop Notification Center and it is unclear whether Apple will also require the removal of that widget.
For the time being, PCalc can be downloaded from the App Store for $9.99, with access to the Notification Center widget included. [Direct Link]
Article Link: Apple Disallows Previously Approved Calculator Widgets for iOS 8 Notification Center