CBOE's (Chicago Board Options Exchange) Options Hub includes a lot of news and educational content and market commentary related to trading options. Twitter: @CBOE
ICE (Intercontinental Exchange) offer Options on UK markets, including most FTSE 100 stocks and the index itself. The forerunner to ICE EU was London International Financial Futures and Options Exchange who ICE acquired in 2013.
The ICE EU site includes details of the main options offered for different underlying assets or commodities (in addition to Futures contracts). Twitter: @ICE_Markets