SureTel is a hosted VOIP provider based in the USA. This app gives our users access to many great features on the go, with many more coming soon. Key features of SureTel Mobile are. Audio Calls. Video Calls. Visual Voicemail. Conferencing. Call Transfer. Call Hold. Mute/ Unmute. Call History. Phonebook. Manage your forwarding settings on the go. See your colleagues status.