Cronofy - Unified Calendar API for developers
Google Calendar - Spend less time managing your day & more time enjoying it
Campaign Calendar - Campaign Calendar by Bracket Labs builds a marketing calendar from your Salesforce Campaigns.
CalendarZ - CalendarZ is a simple yet high-level calendar application, introduced lots of advanced functions and features.
ApPHP Calendar - ApPHP Calendar is a PHP calendar script that may be easily integrated and used with various PHP projects, such as schedulers, event, etc.
CalenGoo - Features | 1.0.175 for Android™