Graphical User Interfaces (GUIs) serve as the primary medium for user interaction with mobile applications (apps). Within these GUIs, editable text views, buttons, and other visual elements exhibit different states following user actions. However, developers often present these states only in various colors without providing textual hints for blind users. This results in significant difficulties for blind users to discern the transitions in component states, thereby hindering their ability to proceed with subsequent actions. Traditional rule-based methods and attribute settings often struggle to adapt to diverse component styles and fail to address the component state changes influenced by context. Recently, pre-trained Large Language Models (LLMs) have demonstrated their generalization ability to various downstream tasks. In this work, we leverage LLMs and propose a tool called C omponent st a te s distinguishing GPT (CasGPT) to automatically distinguish component states in GUIs and provide corresponding textual hints, thereby aiding blind users in app usage. Our experiments demonstrate that CasGPT is a lightweight approach capable of accurately distinguishing component states (accuracy = 86.5%). The usefulness of our method is validated through a user study, where participants expressed positive attitudes toward it. Also, we compare and find that our method outperforms other open source LLMs and different versions of GPT.