The problem is not in Your MySQL or PHP, because its retrieve and print the Special characters correctly in Webpage.
It seems that the problem is in your android client code. You are not parsing the response to correct charset (UTF-8).
If the response from web service is JSON, its default charset is UTF-8, so you need to read the response from ws as UTF8, for Example
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "utf-8"), 8);
If you give additional details or sample codes, Its even more easier to solve your problem
EDIT
Based on your coding, change
responseBody = EntityUtils.toString(response.getEntity());
to
responseBody = EntityUtils.toString(response.getEntity(), "utf8");
You need to mention the Charset while converting your response to String.