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.

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

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

Simple Calendar - A simple calendar with events (optional recurring and reminders), week numbers and a customizable...

Windows Contacts - Windows has many extraordinary organizers, and in the event that you include distributed storage, then you presumably have more.

Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.