All of your builds are recruit level... none of them really pop out as builder+ quality. This app will be rejected.
My suggestion: Forget about these small builds and move forward as an artist. Study the building techniques of the best builders & crafters. Examine small segments of detail and take detailed notes on paper. Consider the usage of the primary elements of art: Line, shape, space, texture, form, value.
And most importantly, shun flat surfaces. The ideal is to transform flat, square Minecraft into flowing, organic works of art.