IPod games are in the form of .ipg files, which are actually .zip archives in disguise. When unzipped, they reveal executable files along with common audio and image files, leading to the possibility of third party games. Apple has not publicly released a software development kit (SDK) for iPod-specific development. Apps produced with the iPhone SDK are compatible only with the iOS on the iPod Touch and iPhone, which cannot run clickwheel-based games. All iPods except for the iPod Touch can function in "disk mode" as mass storage devices to store data files but this may not be the default behavior.
IPod Touch (5th generation) were sold with the iPod Touch include the lanyard for the iPod Touch loop (not available for the 16 GB model). Andrew Williams from "TrustedReviews" noted the 5th generation iPod touch's common features with the iPhone 5, while praising the design and the respectable connectivity. Graham Barlow of "TechRadar" commended the improved screen, more color variants, greater quality earphones and the iPod's light weight while criticizing the "reset" of the lightning port. Scott Stein of CNET praised the enhanced camera quality and design, but remarked that the iPod touch is still weaker and outclassed compared to other iOS devices. IPod