Google Contacts - Google Contacts is Google's contact management tool that is available in its free email service Gmail, as a standalone service, and as a part of Google's business-oriented suite of web apps Google Apps.

Polymail - Native email app for email productivity.

Google Calendar - Spend less time managing your day & more time enjoying it

Morning Mail - A new way to manage your mail. Tinder for email.

Apple Contacts App - Access and edit your contacts from personal, business, and other accounts with the Contacts app.

Airmail - Airmail is a lightweight and lightning fast mail client for Mac.