Quickly sort cards by clicking on the Noteboard Title button in the top left then clicking on the "Sort by..." sub-menu to switch between the options:
Alphabetical
Last Edited
Creation Date
Targeted Date
Date Joined
Child Count
Parent Count
Backlink Coun
Permissions
Content Length
Random
You can also use the arrow button to reverse the order from Ascending to Descending.
If you want to change the sort order more quickly, there's a 'Sort' sub-command in the Command Prompt. Just press 'Cmd / Ctrl' + 'K' to open the Command Prompt, type 'Sort', hit enter and then quickly select the sort you'd like.