Shader not working on Android

We have a problem where our shader works fine in the editor, but if we make an android build nothing happens.

Our shader is a fragment shader that should do a cellular automata simulation. You color exactly one pixel by clicking on it and then the shader expands the pixel in a hexagon like shape.
The fragment shaders output is written into a RenderTexture and then fed back in for further calculations.

Sorry if this code makes you barf, this is the first time we are doing shaders and we have zero ideas why this does not do anything on android. We already played around with minimum API settings,always included shader and set the graphics api to opengles3.

If you have any idea why this is not working, we would really appreciate your help.

Updating the shader

Code (CSharp):

1.         Graphics.Blit(texture, buffer, material);
2.         Graphics.Blit(buffer, texture);

Updating the click

Code (CSharp):

1.  foreach (Touch touch in Input.touches)
2.             {
3.                 if (touch.phase == TouchPhase.Began || touch.phase == TouchPhase.Moved)
4.                 {
5.                     pos = Camera.main.ScreenToViewportPoint(touch.position);
6.                 }
7.             }
8.  
9.             int x = Mathf.RoundToInt(pos.x * pixelSize.x);
10.             int y = Mathf.RoundToInt(pos.y * pixelSize.y);
11.  
12.             material.SetVector("_Click", new Vector4(x, y, 0f, 0f));

The shader

Code (CSharp):

1. Shader "Unlit/GameOfLifeRound"
2. {
3.     Properties
4.     {
5.         _MainTex("Texture", 2D) = "white" {}
6.         _PixelsX("PixelsX", Float) = 256
7.         _PixelsY("PixelsY", Float) = 256
8.         _Click("Click", Vector) = (0,0,0,0)
9.         _SpreadValue("Spread", Float) = 0.1
10.         _Color("Color", Vector) = (0,0,0,0)
11.         [MaterialToggle] _clearToWhite("ClearToWhite", Float) = 0
12.     }
13.     SubShader
14.     {
15.         //Tags{ "Queue" = "Transparent" "RenderType" = "Transparent" "IgnoreProjector" = "True" }
16.         LOD 100
17.  
18.         Pass
19.         {
20.             //ZWrite Off
21.             //Blend SrcAplha OneMinusSrcAplha
22.  
23.             CGPROGRAM
24.  
25.     #pragma vertex vert
26.     #pragma fragment frag
27.  
28.     #include "UnityCG.cginc"
29.  
30.      #pragma target 3.0
31.  
32.             struct appdata
33.         {
34.             float4 vertex : POSITION;
35.             float2 uv : TEXCOORD0;
36.         };
37.  
38.         struct v2f
39.         {
40.             float2 uv : TEXCOORD0;
41.             float4 vertex : SV_POSITION;
42.         };
43.  
44.         sampler2D _MainTex;
45.         float4 _MainTex_ST;
46.         float _PixelsX;
47.         float _PixelsY;
48.         float4 _Click;
49.         float _clearToWhite;
50.         float _SpreadValue;
51.         float4 _Color;
52.  
53.         v2f vert(appdata v)
54.         {
55.             v2f o;
56.             o.vertex = UnityObjectToClipPos(v.vertex);
57.             o.uv = TRANSFORM_TEX(v.uv, _MainTex);
58.             UNITY_TRANSFER_FOG(o,o.vertex);
59.             return o;
60.         }
61.  
62.         fixed4 frag(v2f i) : SV_TARGET
63.         {
64.             if (_clearToWhite == 1)
65.             {
66.                 return float4(1,1,1,0);
67.             }
68.  
69.         float s_x = 1 / _PixelsX;
70.         float s_y = 1 / _PixelsY;
71.  
72.         float4 left = tex2D(_MainTex, i.uv + fixed2(-s_x, 0)); // Centre Left
73.         float4 top = tex2D(_MainTex, i.uv + fixed2(-0, -s_y)); // Top Centre
74.         float4 center = tex2D(_MainTex, i.uv + fixed2(0, 0)); // Centre Centre
75.         float4 bottom = tex2D(_MainTex, i.uv + fixed2(0, +s_y)); // Bottom Centre
76.         float4 right = tex2D(_MainTex, i.uv + fixed2(+s_x, 0)); // Centre Right
77.         float4 topleft = tex2D(_MainTex, i.uv + fixed2(-s_x, -s_y));
78.         float4 topright = tex2D(_MainTex, i.uv + fixed2(+s_x, -s_y));
79.         float4 bottomleft = tex2D(_MainTex, i.uv + fixed2(-s_x, +s_y));
80.         float4 bottomright = tex2D(_MainTex, i.uv + fixed2(+s_x, +s_y));
81.  
82.         if (center.a >= 1)
83.         {
84.             return center;
85.         }
86.  
87.         float spreadvalue = 0.05;
88.  
89.         if (center.a % spreadvalue == 0)
90.         {
91.             if (top.a > _SpreadValue)
92.             {
93.                 return float4(top.r, top.g, top.b, center.a + spreadvalue);
94.             }
95.             if (right.a > _SpreadValue)
96.             {
97.                 return float4(right.r, right.g, right.b, center.a + spreadvalue);
98.             }
99.             if (bottom.a > _SpreadValue)
100.             {
101.                 return float4(bottom.r, bottom.g, bottom.b, center.a + spreadvalue);
102.             }
103.             if (left.a > _SpreadValue)
104.             {
105.                 return float4(left.r, left.g, left.b, center.a + spreadvalue);
106.             }
107.         }
108.         else
109.         {
110.             _SpreadValue *= 1.5;
111.             if (topleft.a > _SpreadValue)
112.             {
113.                 return float4(topleft.r, topleft.g, topleft.b, center.a + spreadvalue);
114.             }
115.             if (topright.a > _SpreadValue)
116.             {
117.                 return float4(topright.r, topright.g, topright.b, center.a + spreadvalue);
118.             }
119.             if (bottomright.a > _SpreadValue)
120.             {
121.                 return float4(bottomright.r, bottomright.g, bottomright.b, center.a + spreadvalue);
122.             }
123.             if (bottomleft.a > _SpreadValue)
124.             {
125.                 return float4(bottomleft.r, bottomleft.g, bottomleft.b, center.a + spreadvalue);
126.             }
127.         }
128.  
129.         //Draw Pixels depending on _Click
130.         float x = round(i.uv.r * _PixelsX);
131.         float y = round(i.uv.g * _PixelsY);
132.  
133.         if (y == _Click.g && x == _Click.r)
134.         {
135.             return _Color;
136.         }
137.         return tex2D(_MainTex,i.uv);
138.         }
139.         ENDCG
140.         }
141.     }
142. }
143.