Lenses like that are not completely unusable, but the off brand ones like that are total garbage. Just like a regular slr lens, ones with good glass are not cheap. Ones that are cheap have bad glass and terrible image quality. I have tons of lenses like that ranging from garbage to ones that cost about 600$ (including a couple or more rare and or obscure ones). I used to use them a lot on fixed lens cameras (typical point and shoot digital though some were pretty good).
The macro ones are by far the most likely to give acceptable results. Raynox makes a popular one.
https://www.pentaxforums.com/forums/lens-clubs/74221-raynox-macro-club.html
Despite having so many, and having gotten a few more to play with since I got a dslr, I just don't ever use them. Dedicated lenses just work a lot better and or are easier to deal with. The only pics I have that I can quick access are taken on a $300 point and shoot (taken 10 years ago before I had a dslr).
My olympus macro (similar to the raynox but mine will vignette on many lenses)
flash_difuser Photo Gallery by Richard Homeyer at pbase.com newmacro-ol Photo Gallery by Richard Homeyer at pbase.com
And a picture of the lens itself (in the first pic its the bigger one)
macrolensfilter Photo Gallery by Richard Homeyer at pbase.com diffuser Photo Gallery by Richard Homeyer at pbase.com
Here is an example of some crappy ones
If the pic says wide or 3x, then its just the camera I think (it was a 3x zoom camera). If it says 1.5x or 3.5x those are teleconverters (I think). Those two are on the crappier side but still probably better than the ones you linked to. I actually don't know for certain what lenses are used but in the pic with the camera it is those 2 lenses (pics were taken 10 years ago).
gradient1 Photo Gallery by Richard Homeyer at pbase.com
Here is am olympus 0.8x wide angle (last image). Olympus makes some decent lenses but they have a rep so some sell for a lot.
wide Photo Gallery by Richard Homeyer at pbase.com
Ultimately, its probably not worth the money for good glass if you have a dsrl (or k-01). It would be better spent on slr lenses (even old AF film ones if you are on a budget). Even the crappier rated lenses that are not reviewed well would look better than a cheap front mount telconverter. If you do care to try some, one possibility would be to look for ones on ebay that fit old obsolete cameras (many have filter thread mounts so they still screw on). They sometimes sell for very little as the cameras they were designed for are obsolete. It is a huge crap shoot what will work though. Most are to small diameter to work on a dslr.
When I get some free time, I'll post some pics on the k-01 with some (maybe tonight if I stay up late but I wouldn't count on it). .