We've looked at various food journals for iOS in the past, and Foodish is the latest entry into this market. It's a food diary that focuses more on providing you a visual record of what you've eaten rather than counting calories.
It's pretty easy to use and has an attractive UI. Launch the app, tap the add button and take a picture of your food or drink. You can group these into meals or snacks, and select whether or not you think you've made a good food choice by tapping a facial expression. You can share the pictures of your meal via Facebook or Twitter.
It's a good, basic program to use if you want to keep a food diary but don't care to count calories. Personally, I gravitate toward more feature-laden programs, such as Lose It (free)