Callmama - Get cheap international calling, international virtual number, Call Mama Gives an added advantage to send message and make calls to non-user of Callmama App.
RingCentral - RingCentral is the leading provider of cloud-based communications and collaboration solutions for small business and enterprise companies
CallHippo - Easy to use Phone System with World-Class Support
Google Voice - Google Voice gives you one number for all your phones, voicemail organized in an email format, free...
KrispCall - Virtual cloud phone system for business
Eir SIP Voice - eir SIP Voice is revolutionizing the core communications tool of business that carries both calls and data over just one connection.