I have created a working iOS8 app extension widget for my app. In the simulator it appears by pulling down Notification Center and clicking edit and adding the widget, however if I compile my app to my iPhone 5S, the widget does not appear in the Notification Center today view until I after I reboot. Each time I compile to my phone I have to reboot again before seeing my widget and re-add it. After rebooting my phone the widget always shows up as expected but before rebooting it is like it does not exist.
Does anybody know why this might be happening? It sure is tedious rebooting after each compile.
This is a known issue in Beta 4 and hopefully will be addressed soon.
After updating a previously installed Today extension, the extension may no longer launch. (17241004)
Workaround: Reboot the iOS device. (source)