The block is available at https://github.com/dthies/moodle-block_deft. Admins will need to install the plugin in the usual way in the blocks directory. After that in the settings the service to update the block contents can be enabled by checking the box, saving and then clicking the activate button.
This should create automatically and preconfigured external tool in Activities -> External tool -> Register tools to deftly. A table showing usage will then be shown in the block settings instead of the button.
You should then be able to add then block to a course or module and when tasks are changed they will be updated in all browsers where they are displayed.