Currently, Equatio does not have an iOS application.
Equatio does have a feature which combines with/inputs to the Equatio desktop/extension toolbar called Equatio mobile which you can read about here:
https://www.texthelp.com/products/equatio/equatio-mobile/
You can also access Mathspace on iPads through this link: equatio.texthelp.com
Be sure to sign in with your licensed school email address when prompted.