Roundcube - Web-based IMAP email client
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
HEY - Email at its best, new from Basecamp.
Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.
Mailo - Mailo is an email client where you can send and receive emails to and from anyone with an email address.
Basecamp - A simple and elegant project management system.