This was taken using my current favourite camera app on the iPhone, Hipstamatic. If you're not familiar with Hipstamatic, it allows you to choose a lens and film, both of which have specific characteristics. For example, the 'Chunky' lens (one of my favourites) simulates the light leakage you might get with a 'toy' camera, while the different films all have their own peculiarities. Ina's 1935, for example, adds a range of red, yellow and green tones depending on the tonal range and balance of the original scene.
The thing I really like about Hipstamatic though, and this is what sets it apart from a lot of the other 'toy' camera apps, is that you need to decide which lens and film you're going to use BEFORE you take the shot. In other words, you need to have some understanding of the different lens and films in order to work out approximately how the shot will appear. For me this is a much better / more creative way of working than simply clicking a whole heap of filter or preset buttons once the shot has been taken.
If you're interested, this shot of a traffic cone was taken using the John S lens and the Pistil film.