This article is written primarily with Windows in mind, though all of the remote solutions we'll be using--except Unified Remote--will also work on a modern version of Linux or Mac OS X.
Unified Remote lets you control your PC with your phone
Simple and slick, Unified Remote is a no-brainer to set up. Just pop over to the Unified Remote website, grab their server application for your PC, and run through the install process. You'll want to set a good strong password, but otherwise everything's pretty much good to go by default. If you're asked to open Windows Firewall for this or any other program presented here, go ahead and say yes. Next, grab the Android app either from the Play Store or by following the download link from the Unified Remote website--which also links to the Windows Phone app, if that's more your style.ot--
Launch the mobile app and--if you have the Unified Remote server running on your computer and your network is feeling happy--it'll try to automatically configure itself; if that doesn't work out, you'll have to manually add your server by entering your PC's IP address.
Once you're connected, dive into the Remotes section of the app. There are lots of options you can play with in here--the two that I've found the most useful are 'basic input', which lets you use your phone's touchscreen as a surprisingly intuitive mouse for the PC, and 'media', which provides play/stop/volume keys that are similar to the ones you might have on your physical keyboard.
It's good stuff, and there's basically no lag if your network connection is stable. The limitation of Unified Remote is, obviously, that it's useful only as a literal remote--you must be looking directly at the machine you're controlling to see the effects of your faux-cursor or media keys.
VLC Remote 'n Stream is the best of both worlds
This app is actually called VLC Direct Pro Free, but I like the 'n because it makes this sound like a discount car wash. If you need one app that can act as both a media remote and a channel for streaming media from your PC to your phone, VLC has the answer--if you already use VLC to handle all of your video-playing needs. And if you don't, you ought to--VLC is open-source, cross-platform, and one of the best media players around; grab it for free from the VLC website.
Now just launch VLC, open Preferences from the Tools drop-down menu, toggle Simple to All in the bottom right, and in the left-hand menu, expand Interface and click Main interfaces. There should be a Web option--check it. Close the Preferences menu, but leave VLC running for the time being.
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