I started working on an app last week for myself. It's geared mainly towards competition (recipes, timelines, cook times, temp, prep, checklists, budget, mileage, calendar, etc).
I could easily modify it to include catering information. I'm only about 25% done, so it is at a stage where changes are very easy to incorporate. Send me a message with ideas that you have:
1. Must have functions
2. Nice to have functions
3. "Wish List" functions