Shelley spent the apocalyptic months between May and September touring the Swiss Alps. She was joined by a group of literary friends, including poets Lord Byron and Percy Bysshe Shelley, who would soon become her husband, as well as writer John Polidari. Spurred by a writing challenge from Byron and the terrible weather, the group wrote ghost stories. Two of those stories, Shelley’s Frankenstein and Polidari’s Vampyr, gave birth to new genres of popular fiction. Meanwhile, Byron and Percy wrote poetry together in a blaze of productivity kindled by their new friendship.

Summer of Darkness offers a fascinating look at the lives of these writers, as well as the events that inspired their creativity that year. The app was built by designer Andrew Sempere and author Anindita Basu Sempere, an American couple who have been living in Switzerland for many years, surrounded by the same landscapes that Shelley and her friends saw two centuries ago. As you read snippets of letters, poems, memoirs, and stories by the group, the app provides beautifully rendered maps to show where exactly each person was as the summer unfolded. Brief flashes of rain and lightning illuminate the screen behind the text, providing a delightful but non-invasive hint of atmosphere. You receive updates to unlock material as the summer unfolds in real time, and if you download the app now you can consume all the past updates in one glorious binge. New updates continue into September.