Mobile phones have become ubiquitous with over 4 billion users worldwide, representing over half of the world's population. Mobile access to the internet is also growing rapidly, with over 2.3 billion users expected by 2025. Libraries must adapt services to be accessible on mobile devices, such as by optimizing websites for mobile or providing access to ebooks, audiobooks, videos and other digital content that patrons can use anywhere. Libraries also need to explore new types of mobile services like augmented reality to remain relevant in the future.