Onesheet CRM - The Simple CRM for Google Sheets
EasyCall Phone Call Center - Instantly provide voice customer support through phone calls.
Followup.cc - FollowUp for email is a lightweight productivity suite that keeps your conversations and tasks from slipping through the cracks. Set perfectly timed reminders that arrive at the top of your inbox, right when you need them.
CloudTalk - Work locally, grow globally
Freshsales CRM - A full-fledged CRM for high-velocity sales teams.
CallKite - Your website’s video call center in just one click.