Tor Refsland writes that Productivity Apps are useless, but he finds 3 essentials for increased productivity:
1) A business calendar/to-do list that you can enter information or thoughts in at any time.
2) A Master ToDo list (Excel will do just fine!). He spends at least 20 minutes per day to update his to do list with new tasks, rearranging tasks, checking off completed tasks. He estimates that saves at least 20 minutes a day x 365 days = 7300 minutes or more than 3 weeks a year.
3) DropBox for storage and syncing. Store the Excel worksheet in Dropbox so all you need is an online connection to access the Master To Do List through Dropbox at any time.
More details here for becoming more productive! http://snip.ly/iaqam