Affinity Photo on iPad seems to colour-manage correctly but only displays results clipped to the sRGB gamut, not taking advantage of the wider P3 gamut on the iPad Pro display. The result is that wide gamut images do not appear correctly, and colours outside the sRGB gamut are not visible.
Steps to reproduce:
Use an iPad Pro model with P3 display.
Create a new document with Display P3 as the colour profile.
Paint some pure red (255, 0, 0) onto the canvas.
Take a screenshot (sleep button + volume up). The screenshot will be in P3.
Import the screenshot into Affinity Photo. The imported document will be in P3.
Sample the red with the eye dropper. Instead of P3 (255, 0, 0), the colour will be P3 (233, 51, 35), which is sRGB (255, 0, 0).