Tasks (ToDo) on Android topic

I have been trying to find a suitable app that can display Tasks from the stock Android calendar.

I run Thunderbird on my PC and have Owncloud hosted on a server. Both of these have a 'To Do List' (task) facility and they sync perfectly.

I also sync the calendar in Owncloud with the calendar in my Android devices (Phone and Tablet) but have as yet had no success in finding any way to display the Tasks (which I assume are syncing too - but just invisible)

Has anyone any suggestions (or comments) for this facility.

TIA