Question: best to do list app for gtd?
Answer: nTask. nTask makes it to the top of our list of the best GTD apps merely because of the fact that this simple to use application has everything that makes GTD implementation smooth for you. ... 
HubSpot CRM. ... 
FacileThings. ... 
Todoist. ... 
Nirvana. ... 
OmniFocus. ... 
Evernote. ... 
2Do.