For those users that have Gimp and would like templates for their icons, I've taken the liberty of converting paulmz's Photoshop templates to Gimp templates. Basically, I replaced the "TEXT" Layer with a TEXT Layer that Gimp understands natively. I also saved all the files as native Gimp files (XCF).
Download the ZIP File here
PS...Paulmz, can you take a look at your 2x1 template please? All the layers have been merged together. It doesn't allow for the TEXT to be changed. I recreated the 2x1 icon in XCF format so maybe you can just use that to make things easier.