Windows: Sometimes you want to keep an eye on something whether it's a download meter or a YouTube video but you don't want to keep the window in question in constant focus. OnTopReplica puts a slice of any window in on-top focus.
After running OnTopReplica for the first time you'll see a large blue window that says "Right Click Here". That window will become the tunnel to whatever window you want to keep on top. Right click to select the primary window (like your browser running YouTube videos) and then select the segment of the screen you want OnTopReplica to replicate. From then out that section of the window you selected will appear on top of all your other applications and windows. You can tweak the opacity and size from within the right-click menu.
One caveat — a very minor one! — is that you'll need to use a separate browser window if you're trying to slice part of a web page. If you switch tabs OnTopReplica replicates that exact space in the new tab. In the screenshot above you seen an Aqua Teen Hunger Force clip I sliced from YouTube. If I switch tabs within that browser you see a slice of the Lifehacker page instead of the YouTube video.
OnTopReplica is freeware, Windows only. Have a clever tip or application for tweaking your interface? Let's hear about it in the comments.