SteemMonsters is the current hot thing at STEEM blockchain. It's a board game where every action is recorded on the blockchain - even though there are not many actions at the moment. But I can call it as a success since it's raised lots of attention and gamers. (and SBDs..)
After @berniesanders' call I have started studying the game. Since there is not much info given yet, I had to investigate these custom JSON transactions and reverse-engineer the website to learn the structure.
With a little bit coding, I index all custom JSON operations of 
See at monsters.steeminator.com
It's not a complete web application yet, but you can:
I have a couple of features in my mind for the next iterations. They're mostly about stats about the game. (Who spend the most, who has the full set, how many cards issued so far, etc.) If you plan to use the app, want to see a feature, shoot in the comments and I can see what can I do.
GL, HF.
team. All the data is gathered from the blockchain.
developed a similar app. See here.