VNC (virtual network computing) has been around for a long time, but lately there seems to be more and more interest in it, perhaps because of all the iPad and iPhone owners who want to connect to their computers back home or at the office.
Screens, from Edovia, is a new entrant in the VNC app race. It is on sale at US$14.99 for a limited time, after which the price will go up to $24.99. The app is universal, so your purchase allows you to install it on both an iPad and iPhone, or an iPod touch.
Like many other similar apps, Screens has support for many multi-touch gestures, as well as squeeze motions to enlarge or shrink the screen back down. The main difference is that with the other apps, you use those gestures to move a cursor around the screen or, in some cases, move the screen around a stationary cursor. Screens allows you to control the remote computer using your finger as a virtual mouse or trackpad.
Of course, you have to run a VNC server app on the machine you want to connect to, and you can find those for Windows and Linux. OS X has VNC built in; you just activate screen sharing in the Mac Sharing preference pane. If you have multiple PCs set up to connect to, you flick between those screens on your iPad, iPod touch or iPhone.
I've tried it at home, and I was easily able to connect to my desktop Mac and a Windows XP PC. Using the app was a pleasure, and because of the way touch is integrated, it felt like a pure multi-touch app rather than a screen emulator. There is a dedicated keyboard, and a second one with keys that relate to the type of computer you are connecting to. For example, you can invoke a Spotlight search with a tap when connected to a Mac.
For Windows PCs, the developers recommend running the free TightVNC on the target machine. I was running RealVNC and could not connect, but when I substituted TightVNC it worked fine.
My experiments were done on my local network, but if you want to connect to your home PCs when you are away from home, there is a free app you can run called Screens Connect that lets you control your Macs or PCs remotely. It's a free download from the Edovia website, and it runs as a preference pane. I could not test it, as the app requires a UPnP or NAT-PMP router. Reports from users are positive.
Screens seems to work as advertised. There are more expensive and less expensive solutions, but I think screens has the best UI and control scheme I've seen.
If you are particularly interested in remote access, I'd also suggest you look at RDM+ for iPad, which works over 3G with no setup. It's on sale for $2.99 for a limited time. The app is not universal, but there is a $1.99 version for the iPhone as well. You must run the RDM+ Desktop software on any PC or Mac you want to access remotely. Other pure VNC options include the pricier iTeleport at $24.99 and Mocha VNC for $5.99.
It's also worth looking at Team Viewer, which is free for non-commercial use. It works fine over the 3G network. but the Team Viewer app nags you constantly about upgrading to the commercial version.
There are lots of options as you travel this holiday season and want to interact with your home or office machine. I liked Screens a lot for the ease of navigating on a remote machine, although RDM+ was the best for dead easy setup. Screens requires iOS4.1 or greater.