What is the best way to store checkbox information?

I have an activity with listview of checkboxes, as you can see on the photo below:

Also, user can add as many items as he wants by clicking add other button. If the user goes to another activity, and then again goes to this one, the checkboxes need to appear in the way the user had saved it. I used shared preferences to save the ones are checked and not checked. But the list can become really long, so is it better to use anything else?