I think this is so. Reading the developer's post it seems he had the idea to use pictures taken with his iPhone, which would include GPS data in the EXIF.
I think this is a fantastic idea.
But yep it just pulls the lat and lon from the EXIF data, so it should work fine. The standard for EXIF is degrees, minutes, seconds and then a separate "Ref" value for N or S.
I have to do a little math on those values to turn everything into a decimal format, but based on this standard I would assume everything saving location in EXIF data would use this same format so it should all be compatible:
http://www.exiv2.org/Exif2-2.PDF (See page 53 of the PDF under the heading GPSLatitude)
If you test it, let me know!
My initial thought was pulling some of my favorite shots from Flickr and using this to find the location of where the shot was taken. Great for finding those hidden photoshoot locations!
Unfortunately most DSLRs do not have the GPS built it. It's usually an add-on attachment.