Unlit transparent shader with alpha property.

TransparentAlpha.shader

Shader "Unlit/Transparent Alpha" {
	Properties{
		_Alpha("Alpha", Range(0.0, 1.0)) = 1.0
		_MainTex("Texture", 2D) = "white" {}
	}

		SubShader{
			Tags {"Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent"}
			LOD 100

			ZWrite Off
			Blend SrcAlpha OneMinusSrcAlpha

			Pass {
				CGPROGRAM
					#pragma vertex vert
					#pragma fragment frag

					#include "UnityCG.cginc"

					struct appdata_t {
						float4 vertex : POSITION;
						float2 texcoord : TEXCOORD0;
					};

					struct v2f {
						float4 vertex : SV_POSITION;
						half2 texcoord : TEXCOORD0;
					};

					sampler2D _MainTex;
					float4 _MainTex_ST;
					float _Alpha;

					v2f vert(appdata_t v)
					{
						v2f o;
						o.vertex = UnityObjectToClipPos(v.vertex);
						o.texcoord = TRANSFORM_TEX(v.texcoord, _MainTex);
						return o;
					}

					fixed4 frag(v2f i) : SV_Target
					{
						fixed4 col = tex2D(_MainTex, i.texcoord) * _Alpha;
						return col;
					}
				ENDCG
			}
	}
}