Dialpad - Switch is a cloud-based phone system built for Google Apps users.
mFax - mFax is a cloud-based fax solution for sending and receiving faxes from any device.
Aircall - Aircall is a call center software of a new generation designed for fast growing companies. Setup instantly and integrates to your CRMs
Hellofax - Easy. Reliable. Online faxing. Send & receive faxes from anywhere.
3CX - Hosted PBX with CRM integration and mobile apps
XM Fax - XM Fax is a file exchange solution that provides companies and users with secure transmission of their highly sensitive documents, including contracts, financial statements, transcripts, legal notices, etc.