PhotoShrinkr for Mac

I am a serious amateur photographer. My Nikon DSLR D7500 routinely creates 15+ meg JPG format files. When I needed to compress a photo I would use one of my photo editors and simply re-save the file with no image changes. I could easily save half of that size. I found Plum Amazing software while searching for something other than photo software. I tested and ultimately bought a couple of their apps. I was working on an on-line photo album that had lots of photos. Actually pictures of headstones in Kentucky cemeteries as part of what I have called "The Cemetery Trail" as inspired by "The Bourbon Trail" here in KY. I was frustrated by the download speed to view the full size files and thought I would try PhotoShrinkr from Plum Amazing. I downloaded the demo and ran it on a sample photo. The original size was over 13 megs. When I compressed it the size was now 2.2 megs. It was so much smaller that it was a bit of a shock. I tried a few more with similar results. One cool feature of the program is a slider that shows the before/after image and you can slide it back and forth to see any change in quality. In my testing I have seen very little difference. For loading to an online photo album this works great. If I was going to have one of my photos printed in a large format I would use the original file. This level of compression is very close to magic for the JPG files that come out of my Nikon. After a few test photos I purchased the app. I even swapped a few support emails with the developer about some questions and got a very quick reply. Sometimes you run across a software developer that really understands how to build great software. Plum Amazing is one of those companies. Highly recommended if you need JPG compression.

Is there a better alternative to PhotoShrinkr? There probably is and if I recall it cost over a hundred clams. Can this app shrink the .jpg without losing clarity?