Wrong Transformation Rendering a Simple Square on OpenGL ES 2 (iOS)

I am learning OpenGL ES2 from the ground (My Reference). I want to render a simple square with the size of 2 at center of the screen.

This is my Square (2 Triangles):

typedef struct {
    float Position[3];
    float Color[4];
} Vertex;

const Vertex Vertices[] = {
    {{1, -1, 0}, {1, 0, 0, 1}},
    {{1, 1, 0}, {0, 1, 0, 1}},
    {{-1, 1, 0}, {0, 0, 1, 1}},
    {{-1, -1, 0}, {0, 0, 0, 1}}
};

const GLubyte Indices[] = {
    0, 1, 2,
    2, 3, 0
};

I setup Layer, Context, Render as some popular Examples on Google.

This is my Vertex shader:

attribute vec4 Position; // 1
attribute vec4 SourceColor; // 2

varying vec4 DestinationColor; // 3

uniform mat4 Projection;

void main(void) { // 4
    DestinationColor = SourceColor; // 5
    gl_Position = Projection * Position;
}

This is my Rendering function:

-(void)render:(CADisplayLink*)displayLink
{
    glViewport(0, 0, self.frame.size.width, self.frame.size.height);
    glClearColor(0, 104.0/255.0, 55.0/255.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT);

    // Setup Projection Matrix
    GLfloat aspect = self.frame.size.height / self.frame.size.width;
    //GLKMatrix4 mat = GLKMatrix4MakeFrustum(-2, 2, -2*aspect, 2*aspect, 2, 100);
    GLKMatrix4 mat = GLKMatrix4MakeOrtho(-2.0, 2.0, -2.0*aspect, 2.0*aspect, 0, 100);
    glUniformMatrix4fv(_projectionUniform, 1, 0, mat.m);

    // Setup color & vertices
    glVertexAttribPointer(_positionSlot, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), 0);
    glVertexAttribPointer(_colorSlot, 4, GL_FLOAT, GL_FALSE, sizeof(Vertex), (GLvoid*) (sizeof(float) * 3));

    // Draw...
    glDrawElements(GL_TRIANGLES, sizeof(Indices)/sizeof(Indices[0]),
               GL_UNSIGNED_BYTE, 0);

    [_context presentRenderbuffer:GL_RENDERBUFFER];
}

I setup Othor Project Matrix with width of 4 and height of 1.77*4 (16:9 of iPhone). I expect an Square in the center of the screen but I get an rectangle instead:

The size and location are not what I expect. What did I do wrong ? I also change to GLKMatrix4MakeFrustum but also receive same result.

You can also download my project here: https://www.mediafire.com/?w0tb74z5tk0xig0

Thank you for reading my long question.