These are the Magento 2 forums -- you'll want to ask your question in http://community.magento.com/t5/Core-Technology-Magento-1-x/ct-p/technology
Mark Shust · ZCE, MCD+
I ll suggest Contus M Comm. It is a readymade mageno mobile app solution that lets store owners to build branded, exclusive, native mobile applications which can be in perfect sync with the online store’s backend. Please have look into it.
I have done a Mobile App for Magento Enterprise site. The best way is that you should contact Magento support: https://magento.com/company/contact-us. They will guide you or may provide Mobile app Android to work with your Magento Api site.