DouWatch is an iPhone application that allows you to watch trending TikTok videos on your Apple Watch. The app is free to download and use, and there is no login required.

To use the app, simply download it onto your phone and Apple Watch. If the app does not appear on your Watch, you can find it in the Watch app on your phone and install it from there. Once you are set up, you can watch currently trending TikTok videos directly on your wrist and save them by hitting the "star" button. You can easily access the saved videos in the iPhone app's "Favorites" tab.

It is worth noting that DouWatch does not breach your privacy in any way. All data is handled safely, and there is no need for a potentially insecure third-party server. For more information on privacy, please refer to the website linked. Additionally, the app offers a subscription for users to support its development, which is optional. If subscribed, the subscription automatically renews after the free trial period, and payment will be charged to your Apple ID account. You can manage and cancel your subscription through your account settings on the App Store.