SpotMenu - Spotify and iTunes in your macOS menu bar
Google Voice - Google Voice gives you one number for all your phones, voicemail organized in an email format, free...
Ring4 - Manage business phone line as easily as you manage emails, in the cloud. Ring4 provide you with a business line and video conferencing solution.
TextMe - TextMe is a free calls and messaging application at both local and international levels.
OpenPhone - Simplest way to own a business phone number
Talkatone - Android App on. Google Play. Stop paying for cell minutes, texts & landlines; Turn your iPad or iPod touch into a phone; Call/Text even in areas with bad cell coverage; Call/Text when travelling without paying for expensive international minutes.