Butterplate is a free and open source, encrypted diary for desktop, which is made on top of buttercup. You can also read Privacy Policy of buttercup.
Butterplate uses only the bare minimum information necessary to function in a user-friendly manner. No data is shared with or sold to 3rd parties. No archive data gets send to our server, it's an offline desktop app. It can only download the software updates if a new version gets released.
Archives are encrypted using extremely strong modern encryption methods by using a password provided by the user. The user is responsible for their password choice in terms of strength. For more details on encryption read Privacy Policy of buttercup.