iPhone: Evomail wasn't a bad iOS mail client when it first launched. It packed in the features that mattered and allowed you to triage your email on the go. Today, the app is relaunching with a completely new interface and feature set.
The big new feature here is the interface. Evomail+ now has a single button contextual interface that load different actions. If you're in your inbox, hit the plus button, and you'll get a different set of options than if you hit it when you're looking at a single email. It gets the job done, even if some of the symbols are nonsense (for example, an up arrow denotes a label).
You can also customise what swiping an email does -- from archiving it to labelling it. Finally, Evomail+ has its own push notification system now, so the app doesn't rely on your own mail server to grab messages.
Like the older version, you can snooze messages for later, easily archive messages right from the main screen, and quickly search through all your mail. Evomail+ isn't as intuitive as it could be, and the symbols it uses for actions are more confusing than they are helpful, but the actual feature set is solid.
Evomail+ (free) [iTunes App Store]