I know many of us are looking for some kind of an ipad app to control sonar, this is even better as you interact directly with the program of choice itself, just like you were sitting at your desk with a mouse. It acts as a virtual screen of your actual computer screen.
This came across my facebook feed today from pro-tools-expert.com
 
It's an app to remotley control your entire DAW PC from your Ipad. It acts as a touchscreen interface of the actual screen on your computer. It works great with Sonar and any other program that you have on your pc as it just emulates your screen and mouse. And it's only $5!!!!!
http://www.splashtop.com/personal
 
As it just takes what is currenty on your regular screen and mimics that on your ipad display, you can play games, send email, run any program you have installed on your machine. Sick Sick Sick, and the cost and ease of setup made it an instant no brainer for me.
I hope someone can get some use out of it.

It's been around at least since the first iPad.

Remote desktop use was around at least as early as Win 3.1

This may be the newest entry in the iPad controller software market http://forum.cakewalk.com/FindPost/3052978

I've been using Splashtop for maybe a year and a half. I've used it on an old Droid 2, an ASUS TF300 tablet, and my current Galaxy Note 2. It's $10/year, but worth it.
 
It has saved my hide a few times. I can think of a few times when I was already out driving when I realized the bass was a touch too loud, or that I forgot to unmute a guitar solo. It's no big deal at all to launch Splashtop, fix the problem (assuming the problems are easy to fix without reliable monitoring), then print a new mix to dropbox or google drive.

I just wish I would have known about splashtop when there were a few discussion threads going around here on the apps people were using to control sonar. I don't think I would have bought DAW remote HD. Not that it isn't a fantastic program for the price, I just like the workflow of the Sonar screen itself (and it is $10 cheaper.)

VNC Viewer I think is (or used to be) free, it works on iPhones as well. I haven't used it in a while though.

Splashtop "phones home" to the company servers every time you use it, so even if you just want to remote to a computer in your home on your own network, Splashtop needs a connection to the Internet to function. And they (the company) will have access to all of your connection records.
 
Alternative solutions like RDP and VNC do not work that way - they don't phone home and only need the local computer-to-computer connection to work.

VNC works great as does RDP internally but it is generally best to set up VPN if you need to use it externally (which I suspect would be a rare requirement). I try to avoid third parties as much as possible when it comes to my data.