Unitely is described as 'service that gathers all of your organization's communication data in one place, such as who contacts who, and on what platform, providing a real picture of employee communications and social relationships in the office' and is an website in the Network & Admin category. There are four alternatives to Unitely, not only websites but also apps for a variety of platforms, including Self-Hosted solutions, SaaS, Windows Phone and Android. The best alternative is Zoho. It's not free, so if you're looking for a free alternative, you could try Nextcloud Hub. Other great sites and apps similar to Unitely are Microsoft 365 (Paid) and Yammer (Paid).
Nextcloud is the most deployed on-premises file share and collaboration platform. Access & collaborate across your devices. As fully on-premises solution, Nextcloud Hub provides the benefits of online collaboration without the compliance and security risks.