The word 'ToDo' has been trademarked by iphone app developer(mytrademarkia.com)
mytrademarkia.com
The word 'ToDo' has been trademarked by iphone app developer
http://www.mytrademarkia.com/todo-77960554.html
http://www.mytrademarkia.com/todo-77960554.html
A trademark simply prevents competitors from using your name in their product. For example, I can't call my tissues "Kleenex" because that name has been trademarked. I can still make tissues, however. If Kleenex had an active patent on tissues, I wouldn't be able to make and market tissues without infringing on their patent.
That's a substantial difference. At worst (for competitors), this trademark will prevent apps being named something like "ToDo List" or "Mobile ToDo". It won't actually prevent todo apps from being sold.