A good examples is Timerdoro.com which uses custom post types to manage objects and social signin for rapid on-boarding. I would not build that by hand.

Another new site is plugindirectory.info. The core of the app talks to an api and charts the results. It took me about 20 hours to build. I didn't have to create pages, user management (registration etc), curl calls, db schema, and so much else. The core of the app took a couple hours, then I just concentrated on the code that actually makes the app.