Apps
You can find a comprehensive list of the latest Steemit/Steem Apps and tools at Steemtools
Is there a Mobile Steem App?
Yes it's called eSteem and you can find it here: https://github.com/feruzm/esteem
What are your favourite Steem Apps?
@roadscape's Steemd : http://steemd.com/
@void's SteemWatch: http://steemwatch.com/
These allow you to analyse Steemit and the blockchain in a variety of ways. Please check them out.