Multiplatform simple app

I need a simple application to work on Windows, Mac and Linux. I don't want JAVA app. Can be in different programming languages for each plaform. Basically the application, just do the follow: - Go into this URL, and get the result: [login to view URL] If user & password is wrong, deny access, and ask again for login details. If login details are correct, that page return the following: {"name":"Full name of the user","user":"username","started":"2013-11-13 16:59:51","workers":10} Result is an JSON array, and then put values of that JSON on different variables, like: - name - email - started - workers During app runtime, will show a time counter, and a float number, calculated based on number of workers. Formula to give after accept work (very simple) On the end of app, simply send back to the server one simple json array with result of calcs, and execution time. I have 500$ to finish that job! I have more $500 if you superes expectations.