Coder experience in Apple, Windows, Android and Ubuntu applications

I am looking for a coder with experience in Apple, Windows, Android, and Ubuntu applications. The ideal candidate should have expertise in the following areas:

- Windows operating system
- Developing new applications
- Improving existing applications
- Apple applications
- Android applications
- Linux & Ubuntu application

Part time and full time opportunity.

If you meet these requirements and can deliver high-quality work, please submit your proposal.