I downloaded this app based on its reviews and the date of its last release, which compared to the other apps in the same category, seemed like one of the best ones. Although from this site, there aren't too many others that it compares to, being that it was free made it the top choice to try out.
Shortly after to my surprise, I saw how much it looked nearly exactly like Onyx - my fault for not paying attention to the developer of the app. Already being a user of the Onyx app for a few years, I was also surprised simply for not being aware of this app.
After checking the tabs and the various features it showed, I quickly uninstalled it, since it pretty much seemed like Onyx but lighter maybe, or rather the same thing but not as many features that Onyx does. To be fair, however, I didn't give it much attention and time to check it out further than I did, so I might be wrong in my opinion of this app.
That being said, if it is really just a light version of Onyx, I cannot honestly know where to begin what to question about it. Just to name a few things, why is it given high ratings, why does it even exist (it would make sense if it was called something like Onyx Lite for example), why are both apps free. Who doesn't love free apps especially when theyre solid and good at what they do, so please don't get me wrong on that point. I am just feeling confused on this app on many levels. In my opinion, Onyx is more of a maintenance app, however it does several other nice things as well. But for my own use, it's always been for maintenance purposes and when it comes to using an app that does "reveals hidden features of the OS", I totally think of different types of apps as that is something different all together. I know other similar apps like to do both things as well, but they do a better job at separating maintenance stuff and hidden features stuff. I just think that both purposes should not be included in the same app which is going beyond the scope of my comment.
I love Onyx and it's always been free. I've never had any issues with it as a maintenance tool, but as for Deeper, if they are equally good it's not enough for me to feel right giving high ratings for both. So I recommend going with Onyx and staying away from Deeper.