You can have iOS 10 say what you’ve just typed. In Settings, go to General > Accessibility > Speech > Typing Feedback. The options under Character Feedback on this page tell iOS to read out individual characters or accented ones. Just below them, you can instruct it to read out whole words after you type them, too.
There’s also an option to speak auto-corrections that are made to your text, and another to hold on a predicted item in the top row of the QuickType keyboard to have it spoken.