You can run Celebrant Assist on Apple Macs/Macbooks but not iPads.
The latest Macs/Macbooks come with a program called Boot Camp which allows you to start your machine as a MAC or as a Windows based PC.
Alternatively, you can use a Windows emulator, also known as a virtual machine, which runs Windows as an application under the MAC operating system such as Parallels Desktop, VMware Fusion, CrossOver, and others.
The advantage of Boot Camp is that you don't need any other software other than a copy of Windows. The disadvantage is that you can't switch between MAC and Windows without restarting your machine.
The advantage of an emulator is that you can switch between MAC and Windows without restarting your machine. These include Parallels Desktop and VMware Fusion. The emulators are reasonably inexpensive but you will also need a copy of Windows.
Both methods require a copy of Windows.