To-Do Apps

I don't like stupid mistakes. To forget something can be frustrating. It is just a Human Error  (Omission :) 
I have used electronic To-Do lists and Calendar for quite some time now. I like to have several list based on topics. Back in the days without mobile internet I had old Nokia phone ( for 5 years! ) and I was happy with it. Then with Android and Google Tasks I have started using GTasks. 
It was really good since I was able to edit tasks also on the laptop and I had a backup in the heavens ( also called clouds ) 
But then things got complicated, the need to share and to sync with family and friends. So I have started to evaluate some new tools.
These were my main requirements:

• Simplicity
• Storage in cloud and Android devices.
• Web interface  - need to edit some of the bigger lists
• Multiple lists ( since there are more areas/categories ) 
• The ability to create a copy of an existing list. 

The last one is very important since we have a generic grocery list ( a superset of things ). Every week we just create a copy of it, check what we already have,  then the remaining items have to be purchased.  Small customization can be done to the list to add new stuff or unique items needed only for that week. ( Extra Belgian dark chocolate for birthdays :P )

I have tried Any.do, Wunderlist, Todoist, but the chosen one is Google Keep, since the other ones did not have the feature of the list copy for free.
A review of the apps above can be found here.