I find apps like this cut a nice compromise. I take security seriously but I’m not going to get into all the anti-virus s/w bullshit.
It should be made clearer what is the nature of this s/w: freeware? shareware? donation ware? or just commercial ware? The way I read that licensing window, it would fit a definition of any one and all of them. It’s perfectly fine to ask people to either donate or buy a license, but this developer seems to be confusing the two. The second niggle is the licensing thing.
My advice is when you see a ‘update available’ alert, cancel out, and zip or copy the version you have to a safe place before doing the update.
If you’re doing security software like this you really can’t be relying on “dialogue” with your users to figure out if you’ve made a major mistake. The main one for me is the developer has a history of releasing updates that really haven’t been tested thoroughly enough. That's the good stuff, but I have a couple of niggles with DetectX. The most important function of this app, and the reason why I’ll keep using it, is the ‘recorder’ - basically, every time you run this app it’ll compare your system set up at that time with how it was the last time it ran and tell you what’s changed. If you know your way around a mac already this function isn’t terribly useful, and if you don’t you probably shouldn’t be messing around in such places, but I do like the fact I can navigate places like LaunchAgents in both ~/Library and /Library in one location and not have to go digging through the Finder. Secondly, it’ll let you easily see in one view some of the diverse places where other crapware hide and execute their bile from. The start up screen lets you do a ‘search & destroy’ on a bunch of common ‘criminals’ (mackeeper, of course, and a few others, though it’s not clear exactly what all of them are). This is a useful app, though there’s a couple of niggles.