Today, when I opened the app (purchased 4 months ago) I received an error message that this app was “damaged” and would need to be deleted and re-installed. Only then did I discover that iSkysoft did not have a record of my purchase. This evidently was due to not purchasing it on their website, but instead through the App Store (which always seems a safer choice for purchasing apps). Fortunately, I did NOT delete it as instructed, but instead went to a list of purchased apps on my Mac, and noticed the opportunity to “update.” I did so, and the app then opened normally. I learned two things: 1) don’t believe the “damaged” app messages 2) don’t assume that the vendor will recognize your purchase. Both surprised me. Had I deleted the app, I doubt whether it would have been an easy task to re-establish my purchase. Not sure who is at fault for this strange sequence — iSkysoft or Apple. Probably both.
Otherwise, I like using this app. I’m not a power user, but it does what I need.