The app is called Habit and is for developing good habits. The theme I have decided on is the human brain. As you probably know, the brain is a funny looking thing. My app is about simplicity and fun, so I would need a couple brain related icons including the main app icon that would reflect the brain, learning, and fun.
If the icons are too complex, the app will feel too scientific and will alienate some users. It should reflect the idea of developing the mind but with a hint of playfulness. The brain is a squishy little blob, isn't it?