SHL21取扱説明書 is a free Android application developed by SHARP CORPORATION that provides a convenient way for AQUOS PHONE SERIE SHL21 users to access their phone's manual even while on the go. With this app, users can easily find the description of the feature they need, using the table of contents, index, and search function. The app also allows users to launch some of the phone's features directly from the description screen. Users can adjust the font size and add bookmarks for frequently accessed descriptions.

It is important to note that this app is exclusively for SHL21 and cannot be launched on other phone models. Users are also advised that downloading and updating the app requires packet communication fees, which is about 5.0MB in size. It is recommended to subscribe to a packet flat-rate service to avoid additional charges. However, users can download the app using the Wi-Fi feature without incurring any packet communication fees.