You can convert your photos to black & white using the Photos app that comes pre-installed on your iPhone. In the Photos app, view the photo you’d like to convert to black & white, and then tap the Edit button in the navigation bar. You’ll then be able to choose from three styles of black & white: mono, tonal, or noir. Tap “Done” to save your changes. You can then select and print the black & white photo using the Tesco Photo app. Once you’ve placed your order, if desired, you can change your photo back to colour by editing it in the Photos app again and then tapping the Revert button.