Pleco is a well crafted Chinese to English and English to Chinese dictionary for iOS devices. The basic free app performs the function of a Chinese dictionary very well. However, the software is unique on the App Store because it is very customisable and allows the purchase of 'Add-ons' to add more features to the dictionary and the sheer number of these in-app purchases that are available is extremely impressive. The most interesting and unique of these features is the Pleco OCR, which allows the use of the iPhone camera to recognise Chinese characters and find related dictionary terms instantly and in real-time.
The OCR module can be found in the 'Add-ons' section of the Pleco app. The module itself costs £8.99 (or £7.99 with the opt-in educational discount) or for $14.99/£12.99.
