I just realized that my iPad Pro iOS 10.1.1 Contacts native app has no underline key in the A slot. Instead, it has an acute accent mark. Not much use in American English. This means I can't enter the email addresses of people whose email addresses contain an underline character. My Gmail keyboard is not missing the underline key, nor are my native apps Notes, and Apple Mail, nor in my app Evermore, app Photoshop Touch, etc.
What can I do about this?