树洞 is the official iOS client for accessing T大树洞, 未名树洞, 北化树洞, and JLU树洞. It offers a variety of features to enhance the user experience.

With 树洞, users can browse posts in chronological order through the timeline feature or opt for a completely random exploration with the "随机漫步" function. The app allows users to engage in voting activities, receive push notifications for comments, favorite posts, and system messages, as well as manage their logged-in devices.

Moreover, users can utilize advanced search functionalities to filter posts by time range and content category, customize their own word or tag blocks, and conveniently view the latest hot posts on their home screen through the widget feature.