This add-on works precisely as advertized. Has allowed me to use several add-ons which this website claims are incompatible with FF v22, and which FF will otherwise refuse to install. Requires no setup and has no options, but simply disables this check.
I would have given a full five stars without hesitation, if not for a few minor issues:
* In the add-on list, it is titled "checkCompatibility," which is badly formatted and confusing because it's the opposite of what the add-on actually does. Something more like the title on this page ("Disable Add-on Compatibility Checks") would be much more appropriate.
* Description is confusing, mentioning the variable name many times while only indirectly stating the primary function of disabling the check, and what this will allow in practice.
* If disabled or removed, the add-ons it facilitated will also be disabled at the next restart. This should be mentioned somewhere in the description or upon disabling, since one might reasonably assume this add-on is no longer needed after the compatibility is confirmed during installation.
I consider this add-on to provide critical functionality which should be included in FF itself, especially considering the frequency of its revision releases and the fact that most newer addons will still function perfectly. Until mozilla allows us to perform "experimental" installations again, this add-on works beautifully. Thanks so much!