How To Mix Your Old iOS Device With New App – If your new app and old iOS device have trouble or not mix you must doing several things for resolve it, what to do, you need to create new iTunes library. and quitting iTunes, launching your new iTunes library again while holding down the Option key, and then choosing to create a new library.
When you do this you'll begin with an empty iTunes library. You'll then need to add to that library any files that you want to sync with your iPod touch--this includes not only apps but also media files. You can do that by dragging the files into the media area of iTunes' Source list. If you don't want to create a second copy of these items, open iTunes' preferences, click the Advanced tab, and disable the Copy Files to iTunes Media Folder When Adding to Library option.
As for updating your apps, I'd suggest doing it from the iPod touch as it won't download incompatible updates. If you do choose to do it via iTunes, I'd suggest taking a long look at my Automator work-around for saving copies of old app.
When others in your household need to use the original iTunes library, simply quit iTunes, relaunch it while holding down the Option key, click the Choose Library button, and navigate to the old library.