The original Hitch Helper was a piece of junk which attached to the hitch and added an unsuitable tire with an inadequate suspension.
I can only hope that it no longer has much of an online presence because this thing has been banished from the road.
The current offering from Hitch Helper
- with or without the motorcycle rack - appears to be a more substantially constructed tag axle assembly with more suitable wheels and tires (except on the ridiculous single-wheel version) and a more roadworthy suspension - it appears to use a Dexter Torflex (just like an Escape trailer) or similar. This is still a very inadequate suspension for the tow vehicle, the vehicle's hitch receiver is not intended for this type of use, and the current non-steering design adds massive scrub during turns.
While it is not a trailer (or dolly) and so there is probably no legal issue for non-commercial use, it is certainly not something which I would allow to be attached to any vehicle which I own.
There is a better-known brand of this sort of junk equipment, if one is comparison shopping.
If the tongue weight of a trailer is too high for the tow vehicle, a weight-distributing hitch (WDH) may be beneficial (removing load from the tow vehicle rear axle is the purpose of a WDH).
If the tow vehicle rear suspension needs to be stiffer to avoid excessive sag, helper springs (air, steel, or elastomer) are available, although these will not increase the rating (allowed capacity) of the axle.