The app is free to download and works on both iPhone and iPad. It allows offline access to the World Register of Deep-Sea Species and currently stores on your device the taxonomic information for over 20,000 deep-sea species, over 350 high-resolution photographs of deep-sea specimens as well as links to online taxonomic tools, sources and important references. We would like to thank our funders and data contributors including the International Network for Scientific Investigation of Deep-Sea Ecosystems, the World Register of Marine Species, the Natural History Museum, and the National Oceanography Centre. We are especially grateful to our image providers, and we welcome contributions to the next version, which we plan to release in coming months.