What you request can easily be implemented using Java, which satisfies your requirement and allow for cross platform usage. And the usage of APIs is a daily routine.
Relevant Skills and Experience
Informatic Engineer, C#, C++, Java Tutor at College and Unity3D (C#) Game Developer
I have worked with C#, C++, Java for many software development firms.
Proposed Milestones
¥300 CNY - Initial Payment
¥380 CNY - Functional Prototype
¥420 CNY - Final Deliverable