Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
Outlook Google Calendar Sync - Offers calendar synchronisation between Outlook and Google, including attendees and reminders.
CircleCI - CircleCI gives web developers powerful Continuous Integration and Deployment with easy setup and maintenance.
gSyncit - gSyncit Outlook Cloud Synchronizer. Outlook Calendar, Contact, Task, Note Synchronizer supporting Google, Toodledo, Evernote, Informant, iCloud, AOL, Yahoo, Synology, Fruux, Memotoo and CalDav/CardDav services.
Travis CI - Focus on writing code. Let Travis CI take care of running your tests and deploying your apps.
EteSync - Secure, end-to-end encrypted and journaled personal information synchronization.