There is now an ongoing Steem directory which tries to list all apps, sites and tools build by the Steem community. It is called SteemProjects and can be accessed at SteemProjects.com.

It's mostly sorted by categories there from tools for account creation, gaming apps like steemgar, steemmonsters, steemsnake and generic steem interfaces like steemit, partiko and musing and is listed here: https://steemprojects.com/categories/steem-interfaces-generic/