IOS – How much storage does iOS 12 require

The exact answer will vary by device, because there are separate iOS builds for each one. The easiest way to figure this out is to examine an iOS 6 install image (a .ipsw file).

The iPad 3 (Wi-Fi only) is the iOS device that is most similar to a Microsoft Surface, although the two are still very different. The iOS 6.0 (build 10A403) install image weighs in at around 1.15 GB.

The IPSW file itself is actually a zip file that contains several files, but most of them are fairly small. The root filesystem disk image, which contains the entire installed OS, weighs in at around 1.12 GB in this case.

Someone with a jailbroken device could decrypt the image and provide a more exact answer, that's a pretty good estimate of the amount of space it will consume on the device when installed.

my daughter showed me an easy way to install the older Apple store apps. you simply log onto the apple store using a computer (without the iPad connected). find & download the software to the library on that computer. once it is added to your library, goto the app store on the iPad & install the software... since the newest version won't work for the iPad, it will ask you if you would like to install the latest compatible version. this seems to work for 85% of the apps out there (as long as there was a prior compatible version). :)