세이고SAYGO is a free education and reference app developed by SAYPEN for Android 13.0 and above. It comes with a Bluetooth-enabled voice pen called SAFE, which can be used to listen to educational content and view images or videos in 3D. The app also features Bluetooth receiving interlocking, allowing direct connection to smartphones and tablets for streaming services.

Using the app is easy with the Three GO method: turn on the app, turn on the pen, and take a book. There are three main benefits of using the app, known as the Three NOs: no need to download pin files, no need to expand memory, and no manual usage required.

However, it's important to note that the app is only compatible with textbooks with the book code function and is not compatible with overseas brand products such as Xiaomi and Nexus. Additionally, the language conversion function is not possible for some languages, and some textbooks may not be fully listening. In the case of the SBS-1000 model, if the pen is not recognized, users can press the Mode button for a long time to switch to video mode, and the model name will appear on the screen. The T button function, which enables translation, is available.