Sherlock Holmes Books, developed by Lettus, is an Android application that allows you to read the original Sherlock Holmes novels and short stories by Sir Arthur Conan Doyle for free. This app includes four novels: A Study in Scarlet, The Sign of the Four, The Hound of the Baskervilles, and The Valley of Fear. It also includes four collections: The Adventures of Sherlock Holmes (12 stories), The Memoirs of Sherlock Holmes (11 stories), The Return of Sherlock Holmes (13 stories), and His Last Bow (8 stories).

The app's main features include the ability to continue from your last read position, dark and light themes, full-screen reading, and the ability to change font typeface, size, and style. You can also bookmark your last read position for each individual book and navigate between chapters using either the drawer or swipe navigation. The app is free to use and offers a convenient way to read the classic Sherlock Holmes stories on your mobile device.