Studio One is not an iPad Compatible DAW, in the sense that you cannot run Studio One 3 on an iPad. You do have other options however for recording onto an iPad and then transferring the audio over to Studio One for continued editing and mastering.
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You do have the option to install the iPad Capture and or Capture Duo Apps that allow you to record to your ipad as well as transfer the recordings over to your Studio One.
http://www.presonus.com/products/Capture-for-iPad
https://itunes.apple.com/app/id892935959
https://itunes.apple.com/app/id892939968
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To answer your other question:
Yes, as long as you have your audio interface setup properly on your Mac... you can use any DAW of your choice. Just need to make sure you set the audio device in the DAW to AudioBox.