It's pretty much impossible to open the references context toolbar to edit an existing reference.

Steps to reproduce:

1. Open an article in VE editing mode on an iPad
2. Tap on any reference footnote in the body of the article – sometimes the reference context toolbar appears, sometimes it doesn't, and sometimes it appears for a second and scrolls away.
3. If you've managed to get the reference context toolbar to appear, tap it – sometimes it takes you to the link inspector, and sometimes it takes you to a new blank citation form

Version: unspecified
Severity: major
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=67390
https://bugzilla.wikimedia.org/show_bug.cgi?id=67637