Skype is a “freemium” communications app from Microsoft that allows you to video chat and place voice calls from computers, tablets, and smartphones. You can also send instant messages, exchange files and images, send video messages, and create conference calls.

Skype is available on Windows, Mac, Linux, Android, Blackberry, iPhone, iPad, and Windows Phone. Due to its popularity and ability to easily record calls, most Podcasters use Skype to conduct Podcast interviews.