Thanks to the HU Admin site, I'm very pleased to be able to provide this tip from Starbys on how to edit submissions to HU on an iPad, iPod touch or iPhone:
"I used health unlocked from iPod most of the time and I noticed the same problem iPad users were having as you mention where once you've typed you can't click back into the text to edit it or change spellings.
I've now worked out that whereas normally you just tap the cursor to where you want it in the text in order to edit, on health unlocked you have to hold down your thumb where you want to edit for a few seconds, rather than just lightly tap it.
Weird but true!
So like you do to select text to copy it, you just press down your thumb hard instead of tapping it, and then the cursor comes up and you can edit the text.
It was good to realise that as it was v frustrating not being able to edit before!
Hopefully HU will fix the issue for apple devices so that only have to tap.
But in the meantime you could advise any iPad users who have this problem (and iPod touch and iPhone) that they can edit the text on HU this way!
I hope this eases the frustration for our Apple users until HU release a proper fix.