If you've ever built an e-commerce or SAAS application, there's a good chance you've provided your customers or users with randomly-generated product keys, invoice numbers, redemption codes, order numbers, etc. Flexkey is a Ruby gem to assist in this process. Consider a standard "Microsoft-style" product key: QPFLS-3OM4I-QQWXS-3QWX0-YQGSP. With Flexkey, generating…

Read more at the source