Portable version of Skype that allows making audio and video calls, as well as sending instant messages, without the need for installation on Windows.

Connect to Twitter directly from your Windows with this client.
Free voice chat app for groups.
Application that allows you to record phone calls, enabling automatic and discreet registration of conversations conducted on the device.
Free, open-source, and distributed communication platform focused on privacy and security.

Exchange text messages and make audio and video calls.