Addial is a small app with one claim to fame: placing calls from the Today panel in iOS 8's Notification Center.
Once you install the app, you'll need to add the widget to the Today panel in your iPhone's Notification Center. You can do this by following the instructions here.
Once it's added, you'll have a small dial-pad that you can dial a phone number with. Tap on the phone icon to place a call or begin composing a message by tapping the text bubble. While I found the numbers to be a tad on the small side, I was still able to dial numbers without issue. Increasing the size of the buttons would be nice to see, as would duplicating the Favorites list in the Phone app within the widget.
Tapping on the app icon itself doesn't reveal much. A simple tutorial on how to activate the widget, with additional icons to create a new contact or send feedback to the developer. It may not be perfect, but it's a quick and simple way of dialing a phone number no matter the app you're using on your iPhone.
Addial is available in the App Store for 99 cents, £0.79, AU$1.29.