This post is titled review, but it’s really more “go use this free and awesome service that all photographers should know about”. That service is lenstag. It’s available as an Android or iOS app or in a browser.
Lenstag lets you register all of your lenses or camera bodies as owned by you. The big reason you want to do this is because if your camera gear gets stolen, you have a record of exactly what you had and the serial numbers associated with them. Anybody buying a second hand lens can check to see if it’s stolen property by checking the serial number on lenstag. This service has already reunited owners with their gear. If you decide to sell your lens, you can transfer to ownership to another lenstag user.
For those of you that are worried about copyright infringement, lenstag has a browser extension that checks the serial number in the metadata for any picture on a site you visit. If images with your camera’s serial number are found, you will be notified and given a link to its location. This means that if anyone is using your images without permission, you have a much better chance of finding them.
To register a lens, all you have to do is enter in the type of lens, the serial number, and attach a picture of the serial number. It only takes about 30 seconds to a minute to enter in each lens, and within a day or two, this information will be reviewed and verified by the lenstag team. Below is a screenshot from the android app showing my verified equipment and 12 new photos of mine that have been found by the browser extension.
In conclusion, go sign up.