What others are there?

Here are some example websites of companies who have created a similar application to what I will be producing:

http://www.todolistsoft.com/
http://www.dextronet.com/swift-to-do-list.php
http://www.effexis.com/achieve/to-do-list-software.htm
http://www.smarttodolist.com/

I will be evaluating and inspecting each application for strengths and weaknesses to that I may incorporate the best aspects of each application. I will also conduct a short questionnaire with a poll of 10 people to see what average users would look for in a time management program.