SO-51D 取扱説明書 allows users to view the user manual and provides convenient features such as launching settings and apps from the displayed pages. Before installation, users are advised to review and understand the following information and then tap on "Update."

When using it for the first time, users need to download this application. It is specifically designed for the SO-51D model and may not function on other devices. Additional packet data charges may apply for downloading and updating the application, hence it is recommended to have a flat-rate packet service to avoid extra costs. The download size is approximately 3.4MB.