VueScan is generally a good program. Though I've had some issues with it. The latest one is the suggestion above that it installs a Photoshop plugin. It, in fact, does not. The plugin does exist, but you have to install it manually, as you do the application itself.
To find the plugin, right-click/Option-click on the application and select Show Package Contents; inside you'll find only the Contents folder; open this and you'll see the Plugins folder; wherein you'll find the Vuescan.plugin file. The easiest way to move this to the Photoshop Plug-ins folder is to select it and copy it to the clipboard (Command-C). Then open the Photoshop folder, navigate to the Plug-ins folder; open this folder, and paste the file (Command-V) to the folder. Thereafter it should (it did for me) show up in the Photoshop File>Import pop-out menu. I found very few items in the CC2019 plugins folder. No Import/Export folder as in past versions. Nevertheless, VueScan showed up in the File>Import pop-out menu in Photoshop. Over the years Photoshop has often changed the way it does things. To use it you have to adapt to those changes. That's another reason people don't upgrade. They don't want to learn new sh*t.
FYI: here the plugin is specified for Photoshop CC 2019, but it also works, in my testing, in Photoshop CC 2018, which the installation of 2019 did not replace. It also works in Photoshop CS6, though you should remove any other VueScan plugins you find there, including the TWAIN plugin. It also works in Photoshop CS5.5, for whatever that's worth. The point of replacing any old VueScan plugins is so that you can be sure of launching this latest version of VueScan in Photoshop. When you scan an image it will open in Photoshop, as it should do, for editing purposes.
By the way, I did not get this solution from VueScan tech support. They insist that VueScan installs the plugin, which it does not. Perhaps it once did—I found a VueScan plugin in Photoshop CS6; I don't remember how it got there. But I figured this out on my own and tested it. Hopefully this solution will work for you, whatever version of Photoshop you're using. You might also try it in other applications, like Adobe Photoshop Elements, and any other app that has a plugins folder or capability. Just a suggestion, if you like VueScan.
I though to give VueScan a lower score because of how disputatious their tech support turned out to be. But for the most part I think reviews should restrict themselves to the quality of the app, which is what I've done here.