In this paper we introduce a novel assistant for autonomous navigation of partially sighted people. The system, called ALICE, offers information about the location and possible directions a visual impaired user must follow in order to reach the desired destinations. The navigation is completed with a novel computer vision method that is able to detect and classify, in real-time, both static and dynamic obstacles without any a priori information about the obstacle type, size, position or location. The GPS localization is enriched with a visual landmark recognition technique. Finally, through audio feedback a set of warnings is launched so that the user is alerted of potential hazards. For the feedback, audio bone conduction headphones are employed in order to allow the visually impaired to hear the systems warnings, but also other sounds from the environment. At the hardware level, the system is totally integrated on a smartphone which makes it easy to wear, non-invasive and low-cost.