Turtl is a secure, collaborative note-taking application. Users can create notes in Markdown format and share them across all their devices. Files and photos can be attached to individual notes. From there, notes can be tagged and organized into projects. Those who wish to collaborate can invite other Turtl users to view and edit notes in specific projects. All data stored in the Turtl app is encrypted using the industry standard libsodium before being sent to a server, keeping users' data safe and private. The Turtl server is open source. Those interested in increased security may also opt to self-host their own server, rather than using the public servers. The Download section of the Turtl website offers Turtl clients for Windows, macOS, Linux, and Android devices. An iOS version is also currently in development.