Custom touchscreen manufacturer and licensed Apple service provider Troll Touch has unveiled custom-made touchscreen solutions for the latest model of iMac -- both the 21.5- and 27-inch sizes. The company offers both internal, factory-installed touchscreens and user-installable analog resistive overlay units, paired with a 12-bit USB controller and custom cabling. As a service provider, Troll Touch can also do in-warranty repairs on iMacs with the factory-installed touchscreen without violating the warranty.