Simply tap on the grid to enter your shape, then edit the numbers that need editing.
If you wish to undo a line, simply click undo.
No rubbing out or scribbling out needed.
To add in your safety folds or change the side of the colour, simply click one of the buttons down the bottom.
There is also a briefcase to save all your favourite flashing in so as you have fast access to them when you need them.
You can also make any flashing a tapered flashing a the tap of a button.