One distinctive feature of Kanbani is the ability to apply an operation to many tasks at once – move, archive, share, etc.
First, call the menu by holding your finger on one of the cards to be changed.
Then, tap the central button – each card will gain a checkbox.
Check desired cards, call the menu again and finally tap a command button to mass-change them.
You can check cards in different lists or even boards.
As usual, Android’s Back button cancels the selection.
Tip: long tap a checkbox to check/uncheck all cards in the list.