The in-app purchases for GarageBand 2.0 on the iPad and GarageBand 10.0 on the iMac are completely different sets of instruments and sounds. You cannot use the the iOS version on the iMac or the iMac version on the iPad. You will have to buy the extension pack on the iMac as well, unless you had a previous version of GarageBand installed on your mac. Then the "Restore Purchase" command should suffice, see:
Thanks Léonie for your clear and simple answer. I appreciate your time and help.
This has answered my question but there are a couple of things l would like to say about it...
Firstly, this seems to go against everything that Apple is supposed to stand for. When I buy a product in one device, I don't expect to have to pay for the same product in another device or computer (especially when they have exactly the same name!)
Secondly, I feel I've been misled. I was never informed during the purchase process on the iPad that the sound set I was buying was only for that device. Also, I haven't seen anything in the iMac version of GB that informs me that to purchase the sound set will only be for the iMac.
By the way, I did have a previous version of GB installed on my iMac but I moved it to another folder - in case I didn't like GB 10 and wanted to resume using the older version.
I can understand your irritation, but as I see it, it is not really a break in Apple's policy, it is just a very unfortunate and misleading naming of two very different products. I suggest to use the feedback form and write your post above to the developer team. This way, they will know about the problem. Use the form below:
When I buy a product in one device, I don't expect to have to pay for the same product in another device or computer (especially when they have exactly the same name!)
Just a few notes on this: You can use GarageBand iOS on many different devices, as long as they are able to execute the program. My GarageBand iOS is running on an iPod Touch, an iPhone 5s, an iPad 3, with only one purchase. All devices are able to run the iOS operating system and have processors, that can execute the code.
The same goes for GarageBand iLife. It will run on any Mac with an Intel processor, that can run a reasonably new version of MacOS X.
Have you noticed, that both GarageBands do really not have much more in common than the name? The iOS version for mobile devices is mainly a program to play and perform music using the iPad sceen , e.g as a musical touch instrument - as a guitar or keyboard, and you can jam along. The Mac version is better for arranging and mixing music or editing tracks and adding effects, but it does not support playing music very well. You need real instruments.