Shader to flash a 2d sprite to white?

Can anyone direct me towards a simple shader that is mobile friendly that can bloom a 2d sprite to white?

Here is a modified shader from the Unity built-in Sprites-Default shader, which includes the flash color and flash amount properties.

Shader "Sprites/DefaultColorFlash"
		[PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
		_Color ("Tint", Color) = (1,1,1,1)
		_FlashColor ("Flash Color", Color) = (1,1,1,1)
		_FlashAmount ("Flash Amount",Range(0.0,1.0)) = 0.0
		[MaterialToggle] PixelSnap ("Pixel snap", Float) = 0


		Cull Off
		Lighting Off
		ZWrite Off
		Fog { Mode Off }
		Blend One OneMinusSrcAlpha

			#pragma vertex vert
			#pragma fragment frag
			#pragma multi_compile DUMMY PIXELSNAP_ON
			#include "UnityCG.cginc"
			struct appdata_t
				float4 vertex   : POSITION;
				float4 color    : COLOR;
				float2 texcoord : TEXCOORD0;

			struct v2f
				float4 vertex   : SV_POSITION;
				fixed4 color    : COLOR;
				half2 texcoord  : TEXCOORD0;
			fixed4 _Color;
			fixed4 _FlashColor;
			float _FlashAmount;

			v2f vert(appdata_t IN)
				v2f OUT;
				OUT.vertex = mul(UNITY_MATRIX_MVP, IN.vertex);
				OUT.texcoord = IN.texcoord;
				OUT.color = IN.color * _Color;
				#ifdef PIXELSNAP_ON
				OUT.vertex = UnityPixelSnap (OUT.vertex);

				return OUT;

			sampler2D _MainTex;

			fixed4 frag(v2f IN) : COLOR
				fixed4 c = tex2D(_MainTex, IN.texcoord) * IN.color;
				c.rgb = lerp(c.rgb,_FlashColor.rgb,_FlashAmount);
				c.rgb *= c.a;
				return c;

Would it be possible to modify this shader so you could have a black outline around the sprite?