LeashTime's Key Management System allows you to manage up to 10 copies of a set of keys for each of your clients. Using it you always know where every key is, whether it is in your office key safe, with a sitter, or with a client. Each key has its own barcoded label.
The system is very full featured. For more detail please see: https://leashtime.com/info/?q=node/5 and be sure to click on the Screen Shots button and the "Explore Key Management Features" box.
For more information on printing and scanning LeashTime barcoded key labels please see: http://training.leashtime.com/LeashTimeBarcodedKeys.pdf