I think I first saw this anchor trolley kit on a Facebook page. The inventor was sort of polling his audience to see if there was enough interest in it to pursue makings molds and manufacturing them.

What caught my eye was the ring release mechanism itself and how flat it allowed the trolley to mount along the side of a kayak neatly. Then, too, note the system uses some hardware clips to keep the lines tracking along the sides in place and not twanging around. Anyway, a nice system. Look here:

Neat Anchor Trolley System

Another device, the Deeper Fish Finder, I was not familiar with is a floating fish finder about the size of a small orange. In videos I have seen, it can be cast out then reeled back in, results viewed on a smart phone, or it can be hanged off the side of a kayak with a little flexible holding device. I saw one deployment where someone was using a remote control toy boat to pull it around to get a look. I'm not sure how well it does finding fish but it apparently reads the bottom very well and its depth. Here it is with the Flukemaster reviewing it:

Deeper Fish Finder


Brad

I have something like that fish finder ball, I bought it last year sometime but only used it once. I have a kayak and bought a fish finder for that, thinking about selling it soon. I agree with you on this, a person definitely needs a anchor trolley and a fish finder. http://www.amazon.com/Vexilar-SonarPhone-with-Transducer-Pod/dp/B00XIUOID4

Not too impressed with that anchor trolley system. It does look neat and orderly which is good for those perfectionist, but in a practical point of view there is too many places of contact that can hang up. It also appears that the line must be kept tight for it to work properly and that probably isn't going to happen under heavy use where you'll get natural stretch from use.
Keeping it simple has always worked for me!