With Pattern Keeper you can view and annotate PDF cross stitch charts. There is an initial, month-long, free trial period then there is a one time charge of around 9 USD to continue to use the app. *DISCLAIMER-IMPORTANT* The app is still in beta and works great with some charts but will not work with others. Backstitches and fractional stitches are not supported. Scans and images can be used but only with limited functionality. The app is tested with charts from Paine Free Crafts, Tilton Craf