Sudoku Puzzler Vol. 2 is the sequel to Sudoku Puzzler Vol. 1 and incorporates a few changes. The most obvious change is the art next to the puzzles:
 

Vol. 2 has some feature upgrades:

• Puzzle names can be edited
• Puzzles can be sorted by progress
• Penciled numbers can be sorted within each square

Vol. 2 also enables choosing a number with a number picker:
 
This allows easier one-handed play using just the wheel, for those sudoku-filled train or bus rides.

Check out Sudoku Puzzler Vol. 1 for more screenshots & info!