This is a major update! After collecting all of our user feedback we took Picross back to the drawing board, applied some elbow-grease, and really cranked on the game. We've added features, removed others, and changed some of the basic design altogether. We are very proud of the result, and we are certain you will enjoy these changes!

You must now explicitly tap and drag a scrollbar to use them. Both in game and in the menus. Scrollbars will highlight when you are dragging it.
Updates to the User Interface (removal of previous features, updated color schemes, etc)
Removed ability to make errors. Each puzzle's win condition is to get it exactly right. Only 'picked' cells count toward the puzzle, 'crosses' and 'empty' cells do not.
Removed puzzles with duplicate solutions, or ones that could not be solved through logic.
"Picked" cells are drawn in white while you're solving any given puzzle. When you've successfully solved the puzzle, the game will draw the picture in color.
Removed the Pick/Cross mode buttons. Instead, tap on cells to cycle through the cell's individual states. Tap once on an Empty cell, and it will turn Picked (white). Tap again, and it will be turn Crossed. Tap again to set back to Empty.
Added multicell toggle - simply hold your finger and drag. The selection rectangle will toggle the cells depending on the next state of the starting cell you selected. For example, if a cell is in Picked mode, and you tap down and drag on it, making a larger selection rectangle, all of the cells in that rectangle will assume the next state of the starting cell. In this case, the next state is Crossed (Empty-->Picked-->Crossed), so all selected cells will be crossed, regardless of their current state.
You can now tap on the numbers to the side and the top of the puzzle to mark numbers/groups you've solved. They will gray out when you do so. Tap again to highlight (undermark) them. It helps a lot to the numbers you've solved, especially in complex puzzles!

We appreciate your feedback greatly! Please keep it coming!