What type of license is needed to develop mobile solutions in MDK or SDK for ERP ECC 6.0?

Hello Experts.

I need to develop a mobile application and I want to know:

-> With SAP Mobile Service licenses they are enough to save information in ERP.

-> Digital access is necessary.

I have SAP ERP 7.5 and GATEWAY 7.4 and I´m used cloud connector.

Thank you for your answer.