One frustration I had with using apps on the Apple Watch ($ 399 at Walmart) was that there was no way to display notifications within an app or access the control center. The only way to access one of the functions was to return to the dial.
That changed with the release of WatchOS 5, but I recently found out about it by accidentally contributing to Reddit. Check it out:
The trick is to press and hold down the top or bottom of the touchscreen until a semitransparent preview of the Notification Center (top) or the Control Center (bottom) is displayed. To complete the task, swipe up or down.
You can then interact with notifications or toggle a device preference. When you finish, you will be back in the app that you used previously.