arezendes. It can be done. It's just not as obvious as other apps.
When you take a screenshot on an iPad it will be saved to apple's iPad photos.app.
Open affinity and press the plus sign to import an image. Then you should see 'Import From Photos'.
Press that and you'll find your screenshot under 'Recents'. Press the image you want to work with and do your edits.
When you've finished your edits use export. At the bottom left off the screen, you'll see a 'Share' button. Pressing that will give you options for direct sharing by mail, iMessage, social media. In the list below 'Copy' you can use 'Save Image' to place it in the apple's iPad photos.app as a modified photo alongside the original. I don't know why it doesn't say save to Photos.
It seems a long way round but it becomes second nature after a while.
Is this a solution for you?
Thought I would just update this thread as I came across a very useful Apple Photos extension on the MAS today called ‘External Editors For Photos’ and virtually free at only 79p! Whilst I still loath Apple Photos as a DAM, I can at least now have a seamless round trip to Affinity Photo and back to edit any photos. There's a short video on using it on the Developer’s website here: http://externaleditorsforphotos.tumblr.com/screencast
One tip using EEFP, if you want it to always open Affinity Photo as the external editor you can launch EEFP on it’s own first from the Applications folder and you will get a dialog window open where you can set Affinity Photo to be your editing app of choice.
