// ... code inside an Activity or Application
@override
public void onCreate() {
    // ... some other code
    // Initialize the LaTeX engine. Call of this function will copy the 
    // "TeX resources" from apk into the data files directory of the
    // host application, and parse the "TeX resources", it may takes a
    // long time, you may call it from a background thread.
    if (!LaTeX.isInitialized()) {
        LaTeX.instance().init(getApplicationContext());
    }
}

String code = "\\int_{now}^{\\infty} \\text{Keep trying}";
TeXRender r = LaTeX.instance().parse(
    code,        // LaTeX code to parse
    720,         // logical width of the graphics context (in pixel)
    20,          // font size
    10,          // space between 2 lines (in pixel)
    Color.DKGRAY // foreground color
);

@override
protected void onDraw(Canvas canvas) {
    Graphics2D g2 = new Graphics2D();
    g2.setCanvas(canvas);
    // draw the formula on the coordinate (10, 10)
    r.draw(g2, 10, 10);
}