This app was mentioned in 2 comments, with an average of 1.50 upvotes
For todo lists I heartily recommend Abstractspoon GTD. It is free and can be downloaded from (http://www.abstractspoon.com/tdl_resources.html). GTD implementation is also possible with it, there is a video on youtube showing this(https://www.youtube.com/watch?v=3lMTN3fhVY8). Also it uses tdl files which can be shared in the cloud and accessed with Android apps - (https://play.google.com/store/apps/details?id=hg.hgTdlList&hl=en)
It's also available for Androd: https://play.google.com/store/apps/details?id=hg.hgTdlList&hl=en