Changes

<htmlet>ios10</htmlet>

== Designing the MessageApp User Interface ==

The user interface for the iMessage app extension is going to consist of 9 Button objects arranged into a 3x3 grid using UIStackView layouts. Later in the tutorial, screenshots of the current game status will be taken and displayed in the interactive message bubbles. Due to problems with screenshots and the UIStackView class, the button collection will be contained within an additional UIView instance.