STN UC is a SIP-based softphone for Android that uses Wi-Fi or 4G/LTE connection to make and receive calls and Instant Messages.

Interworking with PortSIP PBX, STN UC support push notification, which allows it receive calls and messages even it was force terminated.

By using Android's existing contact list, STN UC facilitates easy and effective communication management with an intuitive interface that accommodates multiple calls. Call functionality includes the ability to switch between two calls, merge and split calls, and perform attended and unattended transfers. It also supports video conferences without MCU support.

STN UC incorporates advanced security settings which allow for secure call signaling and audio encryption.

It supports up to 1080P video call with H.264 and VP8 codec and supports HD audio call. Codecs offered include G.279, G.711a/u, Opus, AMR, AMR-WB, G.722.1, iLBC, GSM, SPEEX-WB.