I did my iOS upgrade, and understood that the apps would go. Although I did a "back up" to my computer I wasn't sure what that was really or how I was going to get them back, but now I see that it's easy to reinstall them through the App Store, and that's all gone well.
BUT!!!! One lovely app for dd is not currently available on the UK app store - and so isn't appearing in my "purchased apps" screen. Is there any other way I can get it back? (I'd pay for it again if necessary.)
BTW I highly recommend Harold and The Purple Crayon a magical version of a classic American kid's picture book. If it ever becomes available again in the UK. Or you live in the USA.