Which Part app for iPhone and iPad

Do you have service vehicles with specialised parts.? Do your technicians and office staff have problems agreeing on which is the correct part name, description etc? Which part is an easy way of keeping all the information, description, part numbers and documentation such as diagrams and data sheets all together in an easily searched app. Which Part groups all relevant information such as name, part and serial numbers etc together with photo of the part and relevant data sheets. It can be searched in many ways by manual insertion or bar codes.
You can start off with the free app which can be used for small inventories, and then upgrade to the Pro version subscription later through in app purchase.