Both my Todo.txt apps – the Chrome extension and the Android app – require access to all of the user’s Dropbox. This is an understandable cause of concern to many users. However, this access is required due to the open-platform nature of the Todo.txt suite.
A Todo.txt file is not restricted to my apps. By the nature of the ecosystem, it is accessible by all other Todo.txt apps and extensions as well. So, you may use my Todo.txt app on the Android phone, the Chrome extension on the desktop, another Todo.txt app on their iPad, and the CLI on their Mac/Linux desktop.
All these apps may be from different developers. Yet, by following the todo.txt syntax, they are all compatible with each other, and use the same todo.txt file. Restricting app access to app-specific folder in Dropbox would mean that tasks created using one app will only be accessible to that app – making it incompatible with all other Todo.txt apps.
To ensure this continued interoperability, the Todo.txt apps require access to full Dropbox, so you may store your file anywhere and all apps access it equally.