There are some factories that make things like aftermarket touch screen digitizer for the iPhone. Here is the video from MacRumors:
There is significant demand for these aftermarkets parts, since shops that are not Apple Authorized Service Providers are unable to source parts from Apple. Some of these parts are close to the same quality of parts.
Be careful going through the repair process. Only trust the parts that you would trust if you were repairing the device yourself. Some things should be repaired only be Apple, while there is no "real" reason not to replace a broken iPhone screen yourself. Thanks for reading!