Thank you! Glad you appreciate it.
Did my best to keep it kind of abstract, to keep it accessible as possible. 

About the applications that you mention, those are apps that are related to SteemIt. _Service App_ is one of the first names that somehow connects to these project, I guess. (Awesome background + fx at SteemImg.)

Some kind of micro-blogging system, could do it well as a Subchain Application. An inventors App, where they can kind of kickstart their ideas, and it will be 'locked' in the blockchain, aka they can proof, with witnessses, in more than one way. 

Or a digital book writers App, where writers get rewarded for publishing their books on the Subchain, again, there is proof on the chain, for a long time to be. 

Or, what to think of a photographers App? And something I mentioned before I think, a per language / country SteemIt. And that could be done again with lots of other App ideas, all on a Steem Subchain.

Hope this gave you some ideas to how it could develope. It is still part of the undiscovered genious that Steem is. Can't wait for the future to happen...

https://dl.dropboxusercontent.com/u/84666869/steemit/steemthegenius.jpg