Add WTGC

Add WebTorrent Google Cast (WTGC) app to "Who is using WebTorrent today?" list.

docs/faq.md

@@ -90,6 +90,7 @@ WebTorrent is still pretty new, but it's already being used in cool ways:
 - **[CacheP2P][cachep2p]** - Highly distributed cache platform ([source code][cachep2p-source])
 - **[DropClickPaste][dropclickpaste]** - Drop Dead Simple Content Sharing
 - **[LocalFiles][localfiles]** - Share files by pinning them to geographic locations
+- **[WebTorrent Google Cast (WTGC)][wtgc]** - Cast WebTorrent videos to Google Cast devices ([source code][wtgc-source])
 - ***Your app here – [Send a pull request][pr] with your URL!***
 
 #### WebTorrent Product Alternatives
@@ -148,6 +149,8 @@ There's also a list of WebTorrent-powered alternatives to centralized services h
 [cachep2p-source]: https://github.com/guerrerocarlos/CacheP2P
 [dropclickpaste]: http://dropclickpaste.com/
 [localfiles]: https://localfiles.alhur.es/
+[wtgc]: https://wtgc.firebaseapp.com
+[wtgc-source]: https://github.com/FluorescentHallucinogen/webtorrent-googlecast
 
 ## How does WebTorrent work?