We're building a web app, got any advice?

Thanks to Marceli Wac for sending us a question about cron jobs. We love getting mail from listeners and try our best to read interesting questions on the show. 

The goal for Ben's app is simple: let anyone register their intention to show up to the dog park at a certain time so that strangers can have a better chance of arriving at the same time and get some exercise for the pups. What's the simplest web app that would collect the least personal information and reset every 24 hours. Bonus points if we can do it without a database! 

Kristina Lustig, a veteran Stacker, wrote a great blog post for us: I followed my dreams and got demoted to software developer. 

Our lifeboat of the week goes to Mike Nakis, who answered the question: What is the difference between memberwise copy, bitwise copy, shallow copy and deep copy?