Can't transfer app from iTunes library to iPad
The author of an an app is trying to send me an older version. His English isn't great, but it's better than my Chinese, and we manage to communicate. He sent it using an ipa.rar file and an adhoc file. I expanded the .rar file, so it is now an .ipa iTunes file, and managed to get it into my iTunes library. The adhoc file made it to the profile section of my iPad. However, I can't get the app onto my iPad. It shows up inthe apps section when I connect, but I can't drag it onto a screen. And I can't use the checkbox because it's grayed out. The only time it's available is when I highlight sync all apps, but I don't want to lose all the data on my iPad. I'm not really tech savvy, so if anyone has some help, I need it in pretty basic terms.