Apple bringing double-tap gesturing to its WatchOS 10.1 today, which means you can use it on the Series 9 and Ultra 2 watches.
The double-tap gesture is meant to enhance convenience for the users, allowing them to control their watch with just one hand. All they have to do is tap the index finger and the thumb of their watch hand together twice.
This is very helpful in situations when the user’s other hand is occupied, and they can’t use it to perform actions on the watch. It also serves as a nice contactless feature, which can be helpful when the user’s hands are dirty.
Apple listed a number of things the double-tap gesture allows you to do, which can be set as a primary action for the gesture:
For this gesture to work, the user’s display must be awake, and Apple claims it should have “minimal impact” on the battery life of the Series 9 or Ultra 2 watches. The double-tap gesture is powered by the S9 SiP chip inside of the Series 9 and Ultra 2, which is 25% more power efficient than its predecessor. Its 4-core Neural Engine inside of the watches uses a machine learning algorithm that allows it to detect the slightest change in wrist movement and changes in blood flow when performing the double tab gesture.
Source: Gizmodo