TikTok is mainly discussed as a discrete app or in relation to its parent company ByteDance. This view neglects how TikTok and other ByteDance apps maintain and develop ByteDance’s highly complex app ecosystem. This paper therefore positions ByteDance-owned apps as both apps and “platform tools.” As a short-form video app, TikTok allows end-users to watch videos, creators to make and distribute content, advertisers to endorse products, and developers to build app features. As a platform tool, TikTok is a software-based resource that mediates “platformization,” extending TikTok’s economic, infrastructural, and governmental data-centric logic within and beyond ByteDance’s app ecosystem. Increasingly ByteDance’s platform tools rely heavily on AI technology because of ByteDance’s early investments in AI and the growing interest in AI in the cultural industries. We therefore survey ByteDance’s AI-powered platform tools alongside non-AI ones using systematic financial and infrastructural analysis, uncovering how ByteDance’s platform tools expand ByteDance as a multi-sided, multi-layered, and multi-situated platform. Platform tools, thus, facilitate growth along these three dimensions by encouraging platform dependence; interoperability and interdependence within ByteDance’s app ecosystem; and platformization, including “parallel platformization.” Our empirical work ultimately shows how ByteDance uses platform tools to accrue and operationalize infrastructural and economic power,and how apps have moved from discrete objects to interconnected clusters of platform tools.