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What lenses are available for Unity?
If the lens has (a) scope(s) remember to add them to your answer as well.
Rotten Tomatoes Scope
Allows users to search for review articles of movies, directly from the Unity Dash. The information is gathered from the Rotten Tomatoes website.
Installation
sudo add-apt-repository ppa:scopes-packagers/ppa
sudo apt-get update && sudo apt-get -y install unity-lens-utilities unity-scope-rottentomatoes
Source: Softpedia
You can use this lens to search for apps on Google Play.
To install follow these steps:
sudo apt-add-repository ppa:abhshk-btra/rotatingcanvas
sudo apt-get update
sudo apt-get install googleplaylens
Station listings are fetched from the radio.de group of websites thus making over 7,000 radio channels accessible from the lens. When opened the lens offers up a selection of station recommendations, including streams from locations near to you.
The search bar and filter options should let you narrow down available choices quickly, though be warned that the genre list provided is huge.
Clicking on a station result opens the stream directly in Rhythmbox.
Installation Ubuntu 12.10
The lens isn’t included by default but can be easily installed from the Ubuntu Software Center in 12.10.
Skype lens
Search your contacts and start a conversation. It Needs Skype4Py
sudo apt-add-repository ppa:pedro-joao/ppa
sudo apt-get update
sudo apt-get install unity-lens-skype
UUdeLens searches the wiki of the German Ubuntu forum ubuntuusers.de. It is currently only available in German.
See the UUdeLens webpage for how to download and install it.
RuneScape Wikia Lens
This lens searches the RuneScape Wikia webpage. For those who actually still play the game, this tool may turn out to be very useful for quick searching while playing the game--especially if the new Wikia search feature is bugging you!
To install it, add the PPA and install the lens:
sudo apt-add-repository ppa:ryanmichaelmcclure/ppa
sudo apt-get update
sudo apt-get install unity-lens-runescapewikia