You could add a school of Celestial pearl Danios (Celestichthys margaritatus), they generally get 0.5 - 1 inches each and are perfect for small aquariums.
If you dont like the look of them, You could do A couple of endlers livebearers (Poecilia sp.) and a couple of sparkling gouramis (Trichopsis pumilus). They stay around the 1-1.5 inch mark and are also great for smaller aquariums.
Both are too small to eat the shrimp.