Display quality is very low ( looks blurred).

The picture quality is very poor.

I tried using native resolution of my moto-g handset.

But the pictures seems to be blurred.

Are your images larger than the screen size.  When large images are reduced in size, the frequently will appear blurred; also, when small images are made to fit a specific component that is larger than the image, the images will be blurred.  Experiment with   Automatic, Fill Parent   and setting the Height/Width of your images using code.  Perhaps you will find a combination where the images are clear.

Perhaps this is not what you need to know?       A screen capture image would help users in the forum to understand what you are talking about.

see here App Inventor and the Screen Size