Is Proxify a Firefox add-on? Or an app which modifies your global connection settings on Android?

Proxify is an anonymous proxy service. They offer a tool bar add-on that works in FF. The Proxify site does not mention android but I was hoping it would work as an add-on in FF mobile (Nexus 5, 7).

The message I get says the add-on does not work in FF28, maybe it won't work for any version.

I think it's worth checking with them on whether they support the mobile version. Extensions that expect to use features of MS Windows or MacOS may not work on Android (derived from Linux, I believe).