Checkout this branch.
On the installation page confirm it says that the block 'myoverview' plugin is standard.
Confirm Moodle installs the block successfully.
Go to 'Site administration' > 'Users' > 'Define roles' and edit the 'Manager' role.
Look for 'block/myoverview:myaddinstance' and 'block/myoverview:addinstance' and confirm there is an English translation.
Add the block to the Dashboard and confirm there is no warning (the block content will be empty however).
Call it 'block_myoverview' with 'pluginname' being 'My overview'.