Looking for a specific book can be tiresome, especially in bigger libraries. Browsing through unfamiliar shelves regarding to call numbers indeed sets readers back.Through IoT technologies, the iLib Guider combines library cataloguenavigation functions. The user will be guided directly to the shelf where the book is located right after searchingscanning the ISBN code. Through the accurate positioning, this APP even points out which block of the shelf the books is stored. User then can self-checkout on the smartphone, finishing the end-to-end service without assistance of the staff.