I'm usually a big proponent of never paying for something that I know I can get for free, but I make an exception and pay an annual subscription for unlimited use of the OnX Hunt app to determine property information in the field. As Franz and KinTN pointed out, often that information is available on the county auditor's website for free, but I prefer OnX Hunt for several reasons. First, I travel a lot, and I like the convenience of having all of the information easily accessible in one location no matter what state or county I'm in. Also, I've found that the GIS maps on the auditor websites for my county, and several surrounding counties, are extremely frustrating or impossible to navigate on mobile devices, so they can't really be used in the field. Plus, I've encountered many counties that don't have GIS information available on-line to the general public. These and a myriad of other reasons make the premium for the app worth it for me.