Since I also do web development, I know that HTML has support for the full gallery of Unicode symbols. In order to display the cents symbol, the HTML is: ¢s; and for the plus minus symbol it is: ±.
Android has a class, Html, which has static methods for converting strings to and from HTML. For us, the method of interest is: fromHtml. This method: returns displayable styled text from the provided HTML string. Here is how we use it:
static String plusMinusSymbol = Html.fromHtml("±").toString();
Now, plusMinusSymbol, holds the string for the symbol, it can be used any where a String is expected. You can use the HTML for any Unicode symbol.