Square Register

I am working on an application that will act as a guestbook for a historic site. We offer tours and I have made the form calculate the cost and record cash payment. Now, I want to make the form open the Square Register app that is installed on the tablet the form will be open on. It would open the app when a user clicks a checkbox for credit. Does anybody know how I can do this? I have read how you can do it on an android app, but I don't know how to make it work on Zoho