Wikispaces does not have an iPad app, but they do have a mobile-friendly site that was recently updated for a better iPad viewing experience. The updated site has the major navigation functions at the bottom of the screen in order to provide you with more working space on each page. At the bottom of your screen you will now see "home," "recent changes," "pages and files," and "members." The edit button resides at the top of your page. You can edit anything on wiki with your iPad that you would edit on your laptop.
Applications for Education
The updated Wikispaces mobile interface isn't limited to iPads. It also works on my Android tablets. The cross platform compatibility is a nice feature for schools with BYOD policies as your don't have to worry about one student not having the same editing options as another.