uniform mat4 u_Matrix;
attribute vec4 v_Position;
attribute vec4 v_Position1;
attribute vec2 a_texCoord;
attribute vec2 a_texCoord1;
varying vec2 v_texCoord;
varying vec2 v_texCoord1;

void main() {
    gl_Position = u_Matrix * v_Position * v_Position1; /*I guess that
    this is not possible.*/
    v_texCoord = a_texCoord;
    v_texCoord1 = a_texCoord1;
}

precision mediump float;
varying vec2 v_texCoord;
varying vec2 v_texCoord2;
uniform sampler2D u_texture;
uniform sampler2D u_texture2;
vec4 col1;
vec4 col2;

void main() {
    col1 = texture2D(u_texture, v_texCoord);
    col2 = texture2D(u_texture2, v_texCoord2);
    gl_FragColor = col1 + col2;
}

gl_Position = u_Matrix * (v_Position + v_Position1);

attribute vec3 v_Position;
attribute vec3 v_Position1;

void main()
{
    gl_Position = u_Matrix * vec4(v_Position.xyz + v_Position1.xyz, 1.0);

    .....
}