The Attack On Titan editor at Shonen Magazine recently tweeted on the account asking smartphone users to go to the Yahoo! Japan Mobile page to search for any Attack On Titan related words to see what happens.
The post was tweeted more than 7000 times and people who followed his advice found out that Yahoo! Japan was offering an Attack On Titan theme for the Mobile top page for people who searched words related to the show as seen below.
I tried to reset it to its regular theme to see if the special theme will come up when I search in English, but I was not able to get out of Titan theme. Guess I need to call in Levi.