I currently use Wunderlist to help me manage tasks, both repeating and unique. My department is the primary user of this application but it has been used to some degree by a few other departmental leaders as needed. It has been very helpful in working with my team to have a way to clearly list our tasks, while also assigning somebody to the task and a time when it is due. It has been very helpful to be able to attach files, leave comments, add sub-tasks, and have a section under each task for notes. The primary problems it addresses is lack of clarity on tasks (knowing due dates and person responsible) and cutting down the number of on-going email threads. Specifically, with the latter, it's been great to have the ability to have conversations within each task under comments with users and not have to go through the process of finding the proper email thread.