keyview is described as 'If you're not sure what the scan code is for the key(s) you are interested in remapping, fetch and run this keyview program. Note that "keyview" reports the scan code as a decimal value' and is an app in the Development category. There are five alternatives to keyview for Windows, Online / Web-based and Mac. The best alternative is Aqua's KeyTest, which is free. Other great apps like keyview are KeyboardTest (Paid), Keyboard Checker (Free), Full Key Codes (Free) and Keyboard Codes Display (Free, Open Source).
PassMark KeyboardTest allows users to quickly check that all the keys on their computer keyboard are functioning correctly, check the keyboard LED's, look at the internal scan codes being generated by the keyboard and measure typing speed.
Full Key Codes is a little utility to display code informations about each key of the keyboard. The developers know why :-) In a little window, you will obtain for each key down its character, its ASCII code, and the keyboard code in hexadecimal and decimal.