One frustration I used when using apps on the Apple Watch ($ 399 at Walmart) was that there was no way to view notifications or access the Control Center from within an app. The only way to access either feature was to go back to the watch face.
That changed with the release of WatchOS 5, but I only found out about it recently thanks to a random post on Reddit. Check it out:
The trick is to long press on the top or bottom of the touchscreen until a semi-transparent preview of either the Notification Center (at the top) or Control Center (at the bottom) shows up. To finish the task, swipe up or down.
You can then interact with notifications or toggle in device setting. When you exit, you'll be back in the app you were previously using