UltraVNC is not available for iPhone but there are plenty of alternatives with similar functionality. The best iPhone alternative is AnyDesk. It's not free, so if you're looking for a free alternative, you could try VNC Connect or NoMachine. If that doesn't suit you, our users have ranked more than 50 alternatives to UltraVNC and 17 are available for iPhone so hopefully you can find a suitable replacement. Other interesting iPhone alternatives to UltraVNC are LogMeIn (Paid), Zoho Assist (Freemium), join.me (Paid) and Jump Desktop (Paid).
iTeleport is a magical app that lets you access your computer from anywhere in the world. Supports Mac, Windows, Linux and all VNC servers. See your computer screen and control its keyboard and mouse from wherever: a few feet away, or even halfway around the world.
Remoter is Remote Desktop Client for Mac and iOS. Connect to all your VNC (Screen Sharing), RDP (Windows Remote Desktop), SSH and Telnet sessions from one app. Supports audio streaming for OSX and RDP. Feature Highlights:
Web conferencing, video conferencing, live streaming and remote support servers. Unlimited users. You own it. In-house security & branding. 3-10 month payback compared to WebEx & LogMeIn. Easy 15 minute server setup. Top rated conferencing software.