If you want an e-book app that allows you to doodle, you can refer to the following suggestions: iBooks: iBooks is a widely used e-book application that runs on many devices, including Apple and Android devices. iBooks supports handwritten notes and doodles, which can be written and drawn with the built-in pen and drawing tools. 2. Kindle: the Kindle is an app for reading e-books, as well as handwriting notes and doodling. When using the device, the built-in sensor can detect hand posture and adjust the reading mode accordingly to better support handwritten notes and doodles. Kobo: Kobo is an e-book application similar to the Kindle that also supports handwritten notes and doodles. Kobo's application provides more functions such as reading progress bar, bookmark, and table of contents. It also supports multiple reading modes. These are some of the popular e-book applications that support handwriting doodles. Which application to choose depends on the individual's needs and the type of device.