I have seen all 12 inventions (prototype) on line at Edison nation website. I am also a Gold member there but I don't dare to spell out what I really think of the season 2 inventions on their forum.
But I can do it here.

I have my opinion on everyone of them
AB-belt I like the concept and I think it will be easy to build. Low cost as well. Market it a little bit and it can be a hit.
Cat jungle-gym I have my doubt on this one since I don't actually own a cat, although my mom in law has one. I think it will works on cat's front claws but not sure it works on the rares. Need to see more info.
Dog leash I won't use it, I like to walk my dog with my hand on the retractable leash. I really need that kind of control and some time the buffer zone for him and me. (Hand can extend out further than elbow).
Picture hanger I think that's a perfect example for over engineering. The control on his prototype is tedious. I really hope EE engineer team can come out with some better design.
Bag buddy Sorry, I won't use it. It's just too much trouble to bring this buddy to shopping. I would just use my hands and maybe just roll the shopping cart to my car. (What a great idea?)
Cord-X Yeah, that's a good idea. I like it and I like it a lot. But I probably would just lay cable on ground; yet I am pretty someone will use it.
Bubble machine This is really not my thing. I will pass.
Speed bandage If I operate a client or hospital then I will use the bandage thing. But not for myself or family since I believe each bandage should be in separate seal so I can be sure they are sanitized. Don't get me wrong, I like the idea and I think that's the way should be for hospitals.
Book cover Common, I have seen better book covers. And I doubt there is a big market for book cover. I used them when I was grade student, but never since.
Skate Scepter Like it. Make it with plastic to save weight and use a electrical motor, many kids will use it.
Bouncing alarm clock I don't need it, but I like it a lot. Good idea.
Ping Pong It's cheaper than getting a real ping-pong table, and it's easier to keep. I think it's a good idea. Maybe will give the old ping pong game a new spin.