The freemium iOS app Talkler bills itself as "email for your ears." By reading messages aloud, the app enables you to catch up on email while exercising, driving, cooking, or otherwise busy. The app works as promised, though I ran into issues with setup and voice commands.
Talkler is designed to make setting up your email account painless. In theory, all you have to do is enter your email address (such as email@example.com) and password. But Talkler doesn't currently support Gmail's two-step verification, making my Gmail setup cumbersome. I had no problems setting up my Yahoo account (for which I haven't turned on two-step verification), though. Talkler also supports Hotmail, AOL, iCloud and (for $3/month) Microsoft Exchange.
You can adjust the speed with which your messages are read. Don't expect Siri-like humanity, though, as the voices sound semi-robotic.
Voice controls (such as "Hey Talkler, skip to the next email") add to the hands-free convenience. But at times, Talkler had trouble understanding my commands, even when I was in a quiet office with no background noise. So it's more accurate to say the app is "mostly" hands-free.
Talkler displays your email messages Teleprompter-style, scrolling as it speaks. So if you have to take a quick look, an occasional quick glance should be sufficient.
The app also lets you respond to email with a voice recording, sent as an MP3 attachment; delete messages with a voice command or by pinching on the screen; and tap the screen to pause the reading, go back to the previous email, or jump to the next message. I couldn't find a way to create new messages, however.
Talkler has a Pro version that removes ads for $2/month or $20/year. If you plan to use Talkler frequently, you'll want to upgrade, as the ads are like annoying TV commercials you can't skip.
Too bad Talkler is only for iOS. There are some read-aloud Android apps, such as Voice Reading, but I haven't found one that's email-specific. At any rate, Talkler is worth trying.