This is ideal for professionals who prefer to continue using email, but want the experience to be quicker and more like a chat. The interface is very user-friendly. Review collected by and hosted on G2.com.

Free for personal use, with business plans available on a per-user, per-month basis. It helps save money by bringing together several tools—such as email, chat, and calendar—into a single app. Review collected by and hosted on G2.com.