Harmony Link, an app from Logitech, is available for free at the App Store. It requires Harmony Link hardware, which Logitech (Nasdaq: LOGI) offers for US$99.99. There are several apps for iOS that can turn your iPad or iPhone into a remote control. Most of these are special-purpose apps -- they control just one device. Whether the app controls your DVR like Xfinity\'s application, your PC\'s cursor (Mobile Mouse) or iTunes (Apple\'s own Remote), you\'re hooked up to a single device, usually through WiFi. But unless it has a little extra help, an iPhone or iPad can\'t be a truly universal home theater remote because it doesn\'t have the right hardware. You can use Remote to surf your iTunes library until the break of dawn, but when it\'s time to actually turn the TV off, you\'ll have to start fishing through the couch cushions or -- the horror! -- stand up and schlep all the way across the room. Logitech, however, offers a device that gives iPads and iPhones all the help they need to be fully functional all-purpose home theater remote controls. Its Harmony Link system combines a free app with a very-much-not-free peripheral to enable the complete control of a home theater entirely through an iOS device. To use the Harmony Link app, you need to have a home WiFi network with at least a moderately strong signal in the room with the TV you want to control. You\'ll also need the Harmony Link module, a cookie-sized piece of hardware that plugs into the wall. The setup process involves hooking the Harmony Link module up to your computer via USB. Direct your computer\'s browser MyHarmony.com, a Web app that guides the action. This is what you\'ll use to teach the module absolutely everything about your home theater setup. It needs to know your WiFi password. It needs to know component manufacturer names and model numbers. It might even ask you to point one of your original remotes at the module and hit a few buttons. Finally, it needs to know every setting for every device for every activity you use your home theater for. For example, when you just want to watch straight TV, what input is your TV set to? What about your receiver? Video game system on or off? What controls the volume when you do this -- receiver or TV? Rinse and repeat for every \"activity\" you use it for -- video games, DVDs, Blu-ray, etc. It\'s tedious, but it\'s necessary, and maybe I\'ve made it sound more complicated than it actually is. Logitech\'s Web app for walking you through the process is very smooth. Once you\'re finished, you\'ll also need to download the Harmony Link app to your iPhone or iPad (or both), sync it up, then take the Harmony Link module to your TV room and plug it into the wall. If everything was done right, you\'re ready to go. This whole process will sound familiar to users of other devices in Logitech\'s Harmony line. The company makes several remote controls that are programmed in the same way but are designed as traditional clickers. I\'ve been using one of its more basic models, a Harmony 650, for a couple of years. Even the most expensive models don\'t offer as rich an interface as the Harmony Link system for iPad. But when I settled in with the iPad/iPhone system, I found Harmony Link to be cumbersome and distracting compared to Logitech\'s traditional remotes, many of which cost much less than the Link. One thing that didn\'t let me down was Harmony Link\'s versatility, especially when used with an iPad. The app\'s main directory is a menu of available TV shows, but if you hit the TV button in the upper right corner and turn your system on, a slim mini-set of controls slides in on the right side. Swipe it toward the left and you\'ll see more controls -- basically the same control set you get on a standard Harmony remote. Give it another swipe and you\'ll get a full list of all functions for all components in your system. There\'s even a search bar to find which command you want. I was also impressed with the Link\'s responsiveness. Every button press and command was executed immediately -- no blips or missed signals. The Help button is probably one of the most-used buttons on standard Harmony remotes. It automatically fixes the situation if something\'s gone wrong -- a component didn\'t get a signal, got put on the wrong setting, or whatever. Just keep mashing the button until everything\'s working. Harmony Link has it on both the iPhone and iPad versions. On the iPhone, the app\'s interface is limited to controls, but the iPad version serves as a \"what\'s on now\" list, based on the cable provider you specified in the setup process. Programming is separated into various categories -- Movies, Sports, News, etc. -- and can be scanned several hours in advance. There\'s no direct DVR control here, though. In order to get into your DVR settings, you\'ll need to use the app like a regular remote and work with the interface presented on the TV screen. But those advantages weren\'t enough to convince me to replace my standard Logitech Harmony remote with Harmony Link. My first problem involved positioning the module. It depends a lot on the shape of your room and the layout of your equipment. Logitech says you may be able to set the puck on top of your cabinet and still reach all your equipment by way of bouncing the signal off walls. But my living room is oddly shaped, so the only solution I could find was to go line-of-sight and set the module on the table next to the couch -- very close to my head.That\'s when I learned that this thing makes a noise. It\'s very high-pitched, so not everyone will be able to hear it, but I can, and when I\'m sitting next to it, I can\'t unhear it. Even when I\'m watching a show. And it continues to wheeze whenever it\'s plugged in, even when I\'m sitting on the couch trying to silently read a book. For now I keep it unplugged when I\'m not watching TV, so I end up digging around for the wire whenever it\'s time to settle in for viewing. Sight and touch have also turned me away from Harmony Link. I like having quick-draw access to pause, resume and volume controls that I can feel under my fingertips without looking. I also like the ability to use the remote during a dark scene without getting belted by the shine of a 10-inch backlit screen when all I want to do is turn the volume up a little. With Harmony Link, depending on your brightness and autolock settings, making any kind of adjustment may involve unlocking your iPhone/iPad, squinting, punching in your code, resuming the app, finding the command, and touching the screen. I find it much easier to have a dedicated remote with real buttons. Harmony Link works, and for someone who really wants to control a complete home theater through an iPad or iPhone, it will make that happen. It will put a complete, feature-filled remote in your iPad and obey your every command with sharp precision. It sounds like a very elegant arrangement, but the more I actually used it, the more I missed using a single-purpose, traditional Harmony remote. If you\'re thinking about going ahead with Harmony Link, consider the arrangement of your room and whether you like being able to use a remote in the dark without looking at it. If Harmony Link still intrigues you, go for it. If any of that gives you pause, though, take a look at the Harmony 650 -- it can be found for about half the price of the Harmony Link system.