As pointed out in #2, [extend-left-box already works with GNOME 3.6](https://github.com/StephenPCG/extend-left-box/pull/2#commitcomment-2073340). The metadata.json should be updated to allow installation under this version, too.
As pointed out in #2, extend-left-box already works with GNOME 3.6. The metadata.json should be updated to allow installation under this version, too.