Here is another idea that will work well for the summer festival season and it has something to do with drink too! The Beermometer is an app that will let you know when the beer or wine has reached the perfect temperature to drink.
This is what the Beermometer can offer the user;
The Beermometer is a revolutionary application, which utilizes temperature decay to accurately determine the time it takes for your beer (can or bottle) or wine to reach a desired temperature.
This is a paid for app costing $1.99 in the US and £1.49 in the UK.