The promo is starting on 10 A.M. EST June 10, 2014. They are giving away the codes to redeem subscriptions for 1 Year of Task Synchronisation and Sharing (equals 10 USD).
The 10000 Codes Give Away page: http://www.todochecklistapp.com/10000giveaway
To Do Checklist is the free, stylish task manager with task sync and advanced sharing capabilities, that among others include sharing over Facebook.
To Do Check List iTunes Link: