Arty

Arty is the photo editor for artists.
Unlike other photo editors, this app stays with you beyond just applying a filter. Compare your artwork to your reference with the camera, pick out and match colours to your pencils, zoom in to details, and even track how long you've been working on your project.
ALL FEATURES:
▸ Compare your photo reference to your artwork using your iPhone or iPad camera
▸ Colour matching
▸ Faber-Castell Poloychromos
▸ Prismacolor Premier
▸ Caran d'Ache Luminance
▸ Create a colour swatch to keep track of colours
▸ Filters specific to an artists' needs
▸ Graphite
▸ Outline
▸ Sketch
▸ Shadows
▸ Posterise
▸ Sepia
▸ Vibrant
▸ Pointillism
▸ Pixels
▸ Overlay a grid
▸ Choose the size, opacity and thickness
▸ Choose the grid colour
▸ Full screen mode
▸ Turn your iPhone or iPad into a lightbox and trace the image
▸ Print image variations directly from the app using Apple's AirPrint
▸ Includes any filters and grids you've chosen
▸ Track how long you've been working on the project
▸ Zoom and pan around your image
▸ All settings are saved automatically