HN is notoriously hard to read on mobile, but have you tried: https://cheeaun.github.io/hackerweb/

10 wpm seems really low, I just tested myself on iPhone 5S and easily got between 50 and and 60 wpm. Have you tested yourself? (www.iphonetypintest.com) I wonder if the larger iPhones actually make this harder.

Have you tried one of these? http://thewirecutter.com/reviews/the-best-bluetooth-keyboard...