Merge pull request pcqpcq#226 from Vavassor/master

Add Tusky app

Author: Joker

categories/social_network.md

@@ -121,6 +121,7 @@ App Name                   | Describe                  | Major Language
 App Name                   | Describe                  | Major Language             | Download 
 :------------------------: | :------------------------ | :------------------------: | :------------------------: 
 [Talon for Twitter](https://github.com/klinker24/Talon-for-Twitter) | 100% open source version of my popular Talon for Twitter app on Android. | Java | [![Get it on Google Play](http://i.imgur.com/7sq06lr.png)](https://play.google.com/store/apps/details?id=com.klinker.android.twitter_l) 
+[Tusky](https://github.com/Vavassor/Tusky) | A client for Mastodon, a decentralized social network server. | Java | [![Get it on Google Play](http://i.imgur.com/7sq06lr.png)](https://play.google.com/store/apps/details?id=com.keylesspalace.tusky)
 [Tweetin](https://github.com/mthli/Tweetin) | Yet another Twitter unofficial client for Lollipop. | Java | 
 [Tweet Lanes](https://github.com/chrislacy/TweetLanes) | Tweet Lanes for Android | Java | [![Get it on Google Play](http://i.imgur.com/7sq06lr.png)](https://play.google.com/store/apps/details?id=com.tweetlanes.android)   
 [Twidere-Android](https://github.com/TwidereProject/Twidere-Android/) | Twitter client for Android | Java | [![Get it on Google Play](http://i.imgur.com/7sq06lr.png)](https://play.google.com/store/apps/details?id=org.mariotaku.twidere)