Guys! I almost have it! The lines are antialiased when I comment out the smoothstep part:
gl_FragColor = v_color*smoothstep(0.0, length(fwidth(v_texcoord)), 1.0 - length(v_texcoord));\n
BUT! You need to remove also the fwidth part from this function so in the end the line looks like this:
gl_FragColor = v_color*smoothstep(0.0, length(v_texcoord), 1.0 - length(v_texcoord));\n
The sad part about this solution is that this blurs ONLY the drawDot part:
dot->drawDot(end, DOT_RADIUS / 2.0, color);
The solidPoly is not being blurred:
dot->drawSolidPoly(poly, 4, color);
Why is it so? Or how can I replace the SolidPoly part so I get a line without holes in it? Because when I comment out the SolidPoly part I will draw only Dots and when I move my finger fast I get holes in the line I draw. I’m so close yet so far! 
HELP!