This app is not "automated" in any way or wireless, like some paid apps are. You must hook up your android device to your Mac via a USB cable. I hook up my Galaxy S7 phone to a powered USB hub hooked to my 2015 MacBook Pro which runs MacOS High Sierra.
Here are the steps:
1. When you plug in your device using its own USB cord, the App automatically launches on your Mac.
2. Two pop-up windows appear, one on your phone (Allow access to device data) and one on your Mac desktop (Can't access device storage).
3. FIRST, on your Mac, click OK. The window will disappear. SECOND, on your phone, tap "Allow." Then a window will pop-up on your Mac showing your phone's file structure.
4. Find the files you want under the "Phone" or "Card" tabs at the top. Photos are in the DCIM > Camera folder under each tab.
5. Drag the files from the app window to your desktop or an open File folder window.
6. Once files are transferred, you can delete them on your phone to save space.
Most of the negative reviews are probably from people who don't perform step 3 in the correct sequence. Unless you do, the app will not launch properly.