Mac OS X Softwares to Sync Contacts

Toky is a comprehensive cloud-based phone system designed for businesses, offering voice calls, SMS, call recording, and integrations with various CRM and business tools. It provides teams with a flexible and powerful communication platform for customer support and internal collaboration.

Telzio provides a cloud-based business phone system offering voice, SMS, and fax services. It includes features like Auto-Attendant, Call Queue, Call Recording, and secure VoIP calls, designed for businesses seeking a flexible and scalable communication solution.

Soocial was a cloud-based synchronization service designed to keep your contacts consistent and up-to-date across various devices, applications, and platforms, including computers, phones, and web services.

fruux is a robust cross-platform synchronization service designed to keep your contacts, calendars, and tasks seamlessly in sync across all your devices and applications. It offers a secure and reliable cloud platform with strong privacy focus, ideal for individuals and teams needing consistent data access and collaboration.

Baïkal is a lightweight and easy-to-use CalDAV and CardDAV server, providing a simple way to sync your calendars and contacts across various devices and applications. Built upon the robust sabre/dav library, it offers a straightforward administrative interface for seamless management of users and data.

Nylas Mail, an extensible open-source email client, offers a unified inbox, robust search, and calendar integration. It supports multiple accounts and provides features like email tracking and undo send, aiming to enhance productivity and email management for users.

WeChat is a comprehensive mobile app offering instant messaging, social networking, payment services, and access to a wide range of mini-programs. It facilitates communication through text, voice, and video, supports group interactions, and integrates various lifestyle services.

iCloud is Apple's comprehensive cloud service offering seamless integration across all Apple devices for storage, synchronization, and backup of photos, videos, documents, and app data. It provides a centralized hub for managing personal information, facilitating file sharing, and enhancing security with features like end-to-end encryption.

Nextcloud is an open-source, self-hosted platform for file synchronization, sharing, and collaboration. It provides a private alternative to commercial cloud storage services, offering a comprehensive suite of tools including file management, calendar, contacts, and notes, all under your control.

Postbox is a powerful and customizable email client designed for professionals managing high volumes of email. It offers robust features for organizing, searching, and managing multiple accounts efficiently, enhancing productivity through a clean interface and advanced tools.