Changing List Names on the Website

Both is OK,
To edit names on the website: Select Contents, then open the list you want to change, on the right side the list will open, inside the top box, there is a button that looks like this: , press it to change the name.
On the apps< on iOS swipe with your finger on the name, on Android keep your finger pressed to get the buttons that include the button to change the name.

In all cases, please remember to "Update Cards", that is to synchronize the device with the website!