Tracking Standard Stamped Envelopes?

Hey everyone, quick question. I ship a lot of covers/flats using standard First Class postage (actual stamps, not metered labels), and the lack of tracking has always been a massive headache.

I recently built a small private browser tool "Postal Manager" for my own shipping desk that formats the addresses and generates the official USPS Intelligent Mail Barcode (IMb) right on the envelope, so I can actually track them through the sorting network just like ebay Standard Envelope does.

Before I polish it up, would a tool like this be useful to anyone else here for their own shipping? Trying to gauge if it's worth making public!

Curious as to how having the bar code let's you track mail. Do you have a source of scans from USPS processing facilities?