Apple has introduced a new double tap gesture for its Watch Series 9 and Watch Ultra 2 models. The feature allows users to perform common actions by tapping their index finger and thumb together twice. While the gesture looks cool, there is some skepticism about its reliability. Apple claims to have ensured that the gesture is triggered accurately by using an algorithm that detects wrist movements and changes in blood flow. However, the double tap feature is currently limited and does not work underwater or in certain apps and features.