WorldTrotter looks good, and its map is useful, but so far the temperature conversion view only converts a single, hardcoded value. In this chapter, you are going to add an instance of UITextField to ConversionViewController. The text field will allow the user to type in a temperature in degrees Fahrenheit that will then be converted to degrees Celsius and displayed on the interface (Figure 6.1).

Figure 6.1  WorldTrotter with a UITextField