diff --git a/webapp/src/App.css b/webapp/src/App.css
index 50b63a3..f09c515 100644
--- a/webapp/src/App.css
+++ b/webapp/src/App.css
@@ -16,3 +16,7 @@
 .App-link {
   color: #61dafb;
 }
+
+.Container {
+  margin-top: 25px;
+}
\ No newline at end of file
diff --git a/webapp/src/App.js b/webapp/src/App.js
index 9fac52a..f796e62 100644
--- a/webapp/src/App.js
+++ b/webapp/src/App.js
@@ -1,47 +1,31 @@
 import './App.css';
-import React, { useState, useEffect, useCallback } from 'react';
+import React from 'react'
 import {
   BrowserRouter,
   Routes,
   Route,
-} from "react-router-dom";
+} from "react-router-dom"
 
-import Header from "./Header"
-import Leaderboard from "./Leaderboard";
-import GameProposal from "./GameProposal";
+import Header from "./components/Header"
+import Leaderboard from "./components/Leaderboard"
+import GameProposal from "./components/GameProposal"
+import DataPolling from './components/DataPolling';
+
+//import { UserProvider } from "../contexts/UserProvider"
+//import { GameProposalProvider } from './context/GameProposal';
 
 function App() { 
-  const [games, setGames] = useState(null);
-  const [polling, setPolling] = useState(false);
-
-  const pollGames = useCallback(() => {     
-    if (polling)
-      return;
-
-    setPolling(true);
-    fetch('/api/gamestate')
-      .then(response => response.json())
-      .then(data => {
-        setGames(data);
-        setPolling(false);
-      })
-      .catch(err => console.log(err.message));
-  }, [polling]);
-
-  useEffect(() => {
-    const timer = setInterval(pollGames(), 35 * 1000); // <<-- poll new gamestates every 35 sec
-    return clearInterval(timer);
-  }, [pollGames])
 
   return <div className="App">
     <BrowserRouter>
-      <Header/>
-      <div className="Container">
-        <Routes>
-          <Route path="/leaderboard" element={<Leaderboard/>} />
-          <Route path="/gameproposal" element={<GameProposal games={games}/>} />
-        </Routes>
-      </div>
+        <Header/>
+        <DataPolling/>
+        <div className="Container">
+          <Routes>
+            <Route path="/leaderboard" element={<Leaderboard/>} />
+              <Route path="/gameproposal" element={<GameProposal/>} />
+          </Routes>
+        </div>
     </BrowserRouter>
     </div>
 }
diff --git a/webapp/src/Header.js b/webapp/src/Header.js
deleted file mode 100644
index f9dc7dc..0000000
--- a/webapp/src/Header.js
+++ /dev/null
@@ -1,17 +0,0 @@
-import { Link } from "react-router-dom";
-import './Header.css';
-
-export default function Header() {
-    return (
-      <p>
-        <h1>CordaCheckers</h1>
-        <nav>
-          <Link to="/leaderboard">Leaderboard</Link> {"| "}
-          <Link to="/gameproposal">Game Proposal</Link> {"| "}
-          <Link to="/game">Active Games</Link> {"| "}
-          <Link to="/archive">Archive</Link> {"| "}
-          <Link to="about">About</Link>
-        </nav>
-      </p>
-    );
-  }
\ No newline at end of file
diff --git a/webapp/src/components/DataPolling/index.jsx b/webapp/src/components/DataPolling/index.jsx
new file mode 100644
index 0000000..4b4a789
--- /dev/null
+++ b/webapp/src/components/DataPolling/index.jsx
@@ -0,0 +1,16 @@
+import React from "react"
+import { AppData } from "../../context/data"
+import { AppContext } from "../../context/app"
+
+export default function DataPolling() {
+    const [appData] = React.useContext(AppData)
+    const [appCtx, dispatchAppData] = React.useContext(AppContext)
+
+    return <div className={DataPolling.name}>
+        polling
+        <button onClick={() => dispatchAppData({type: "togglePolling"})}>
+            { appCtx.disablePolling === true ? "off" : "on" }
+        </button>
+        { appData.fetching }
+        </div>
+}
diff --git a/webapp/src/GameProposalAction.js b/webapp/src/components/GameProposal/GameProposalAction.js
similarity index 66%
rename from webapp/src/GameProposalAction.js
rename to webapp/src/components/GameProposal/GameProposalAction.js
index 0fdd4df..0c60782 100644
--- a/webapp/src/GameProposalAction.js
+++ b/webapp/src/components/GameProposal/GameProposalAction.js
@@ -6,11 +6,11 @@ export function Accept({uuid}) {
         </button>
 }
 
-export function Reject({uuid}) {
-    return <button className="action" id={uuid} type="submit">
-        Reject
-        </button>
-}
+// export function Reject({uuid}) {
+//     return <button className="action" id={uuid} type="submit" >
+//         Reject
+//         </button>
+// }
 
 export function Cancel({uuid}) {
     return <button className="action" id={uuid} type="submit">
diff --git a/webapp/src/components/GameProposal/GameProposalCancel.js b/webapp/src/components/GameProposal/GameProposalCancel.js
new file mode 100644
index 0000000..24a562e
--- /dev/null
+++ b/webapp/src/components/GameProposal/GameProposalCancel.js
@@ -0,0 +1,24 @@
+import React, {useState} from 'react';
+
+export default function Cancel({uuid}) {
+    const [pending, setPending] = useState(new Map())
+
+    for (const [key, value] of pending)
+        console.log("cancel", key, value);
+
+    function sendRequest(uuid2reject) {
+        const nextPending = new Map(pending)
+        nextPending.set(uuid2reject, null)
+
+        setPending(nextPending)
+    }
+
+    const status = pending.get(uuid)
+    const isPending = status !== undefined
+
+    return <button 
+        className={isPending ? "visible" : "action"} 
+        onClick={() => sendRequest(uuid) }>
+            Cancel
+        </button>
+}
diff --git a/webapp/src/components/GameProposal/Reject.jsx b/webapp/src/components/GameProposal/Reject.jsx
new file mode 100644
index 0000000..6b59e81
--- /dev/null
+++ b/webapp/src/components/GameProposal/Reject.jsx
@@ -0,0 +1,21 @@
+import React, {useState} from 'react';
+
+export default function Reject({uuid}) {
+    const [pending, setPending] = useState([])
+
+    for (const [key, value] of Object.entries(pending))
+        console.log("pending ", key, value);
+
+    function sendRequest(reject_uuid) {
+        setPending(             // Replace the old array
+            [                   // with a new array consisting of:
+                ...pending,     // - all the old items
+                { uuid: reject_uuid }  // - and a new item at the end
+            ]
+        )
+    }
+
+    return <button className="action" onClick={() => sendRequest(uuid) }>
+        Reject
+        </button>
+}
diff --git a/webapp/src/GameProposal.css b/webapp/src/components/GameProposal/index.css
similarity index 100%
rename from webapp/src/GameProposal.css
rename to webapp/src/components/GameProposal/index.css
diff --git a/webapp/src/GameProposal.js b/webapp/src/components/GameProposal/index.jsx
similarity index 57%
rename from webapp/src/GameProposal.js
rename to webapp/src/components/GameProposal/index.jsx
index 3cd85a6..3e7f25c 100644
--- a/webapp/src/GameProposal.js
+++ b/webapp/src/components/GameProposal/index.jsx
@@ -1,24 +1,25 @@
+import './index.css';
 import React from 'react';
-import {Accept, Reject, Cancel} from './GameProposalAction';
-import './GameProposal.css';
+import {Accept} from './GameProposalAction';
+import Reject from './Reject'
+import Cancel from './GameProposalCancel'
 
-const State = {
-	WaitForOpponent: "GAME_PROPOSAL_WAIT_FOR_OPPONENT",
-	WaitForYou:      "GAME_PROPOSAL_WAIT_FOR_YOU",
-}
+import { AppData } from "../../context/data"
 
-const GameProposal = ({games}) => {
 
-  if (games == null)
-    return <p>Loading..</p>
+export default function GameProposal() {
+  const [data] = React.useContext(AppData)
 
-  // for (const [key, value] of Object.entries(games))
+  if (data.games == null)
+    return <div>Loading..</div>
+
+  // for (const [key, value] of Object.entries(data.games))
   //   console.log(key, value);
    
-  const waitForYou = games
-    .filter(game => game.status === State.WaitForYou)
+  const waitForYou = data.games
+    .filter(game => game.status === Status.WaitForYou)
     .map(game => { 
-      return <div class="li" key={game.uuid}>
+      return <div className="li" key={game.uuid}>
         <p>
           You {Stone(game.myColor)} <i>vs</i> {game.opponentName} {Stone(oppositeColor(game.myColor))}
           <br/>
@@ -30,10 +31,10 @@ const GameProposal = ({games}) => {
         </div>
     });
 
-  const WaitForOpponent = games
-    .filter(game => game.status === State.WaitForOpponent)
+  const WaitForOpponent = data.games
+    .filter(game => game.status === Status.WaitForOpponent)
     .map(game => { 
-      return <div class="li" key={game.uuid}>
+      return <div className="li" key={game.uuid}>
         <p> 
           You {Stone(game.myColor)} <i>vs</i> {game.opponentName} {Stone(oppositeColor(game.myColor))}
           <br/>
@@ -47,7 +48,7 @@ const GameProposal = ({games}) => {
   return <div className="GameProposal">
     {waitForYou}
     {WaitForOpponent.length > 0 && 
-      <div class="separator">
+      <div className="separator">
         waiting for opponent ({WaitForOpponent.length})
       </div>
     }
@@ -55,14 +56,21 @@ const GameProposal = ({games}) => {
     </div>
 };
 
+
+
+const Status = {
+	WaitForOpponent: "GAME_PROPOSAL_WAIT_FOR_OPPONENT",
+	WaitForYou:      "GAME_PROPOSAL_WAIT_FOR_YOU",
+}
+
 function Stone(color) {
   if (color === "WHITE")
-    return <span class="stone">⛀</span>
+    return <span className="stone">⛀</span>
 
   if (color === "BLACK")
-    return <span class="stone">⛂</span>
+    return <span className="stone">⛂</span>
 
-  return <span class="stone">{color}</span>
+  return <span className="stone">{color}</span>
 }
 
 function oppositeColor(color) {
@@ -74,5 +82,3 @@ function oppositeColor(color) {
 
   return color
 }
-
-export default GameProposal;
diff --git a/webapp/src/Header.css b/webapp/src/components/Header/index.css
similarity index 100%
rename from webapp/src/Header.css
rename to webapp/src/components/Header/index.css
diff --git a/webapp/src/components/Header/index.jsx b/webapp/src/components/Header/index.jsx
new file mode 100644
index 0000000..2528bbb
--- /dev/null
+++ b/webapp/src/components/Header/index.jsx
@@ -0,0 +1,17 @@
+import './index.css';
+import React from "react"
+import { Link } from "react-router-dom";
+
+export default function Header() {
+
+  return <div>
+    <h1>CordaCheckers</h1>
+    <nav>
+      <Link to="/leaderboard">Leaderboard</Link> {"| "}
+      <Link to="/gameproposal">Game Proposal</Link> {"| "}
+      <Link to="/game">Active Games</Link> {"| "}
+      <Link to="/archive">Archive</Link> {"| "}
+      <Link to="about">About</Link>
+    </nav>
+    </div>
+}
\ No newline at end of file
diff --git a/webapp/src/Leaderboard.css b/webapp/src/components/Leaderboard/index.css
similarity index 100%
rename from webapp/src/Leaderboard.css
rename to webapp/src/components/Leaderboard/index.css
diff --git a/webapp/src/Leaderboard.js b/webapp/src/components/Leaderboard/index.jsx
similarity index 59%
rename from webapp/src/Leaderboard.js
rename to webapp/src/components/Leaderboard/index.jsx
index f10c1a1..fe0eaf3 100644
--- a/webapp/src/Leaderboard.js
+++ b/webapp/src/components/Leaderboard/index.jsx
@@ -1,22 +1,11 @@
-import React, { useState, useEffect } from 'react';
-import './Leaderboard.css';
+import React from "react"
+import './index.css';
+import { AppData } from "../../context/data"
 
-const Leaderboard = () => {
+export default function Leaderboard() {
+  const [data] = React.useContext(AppData)
 
-  const [data, setData] = useState(null);
-
-  useEffect(() => {
-    fetch('/api/leaderboard')
-      .then((response) => response.json())
-      .then((data) => {
-        setData(data);
-      })
-      .catch((err) => {
-        console.log(err.message);
-      });
-  }, []);
-
-  if (data == null) 
+  if (data.leaderboard == null) 
     return <p>Loading...</p>
 
 //  var listItems = Object.keys(data).map(playerName => {
@@ -28,8 +17,8 @@ const Leaderboard = () => {
 //  });
 //  return <ul>{listItems}</ul>;
 
-  const tableRows = Object.keys(data).map(playerName => {
-    var rank = data[playerName];
+  const tableRows = Object.keys(data.leaderboard).map(playerName => {
+    var rank = data.leaderboard[playerName];
 
     return <tr key={playerName}>
       <td>{playerName}</td>
@@ -55,5 +44,3 @@ const Leaderboard = () => {
     </table>
     </div>
 };
-
-export default Leaderboard;
diff --git a/webapp/src/context/app/index.jsx b/webapp/src/context/app/index.jsx
new file mode 100644
index 0000000..f4be27c
--- /dev/null
+++ b/webapp/src/context/app/index.jsx
@@ -0,0 +1,17 @@
+import React from "react"
+import { reducer, initialState } from "./reducer"
+
+export const AppContext = React.createContext({
+  state: initialState,
+  dispatch: () => null
+})
+
+export const AppContextProvider = ({ children }) => {
+  const [state, dispatch] = React.useReducer(reducer, initialState)
+
+  return (
+    <AppContext.Provider value={[ state, dispatch ]}>
+    	{ children }
+    </AppContext.Provider>
+  )
+}
diff --git a/webapp/src/context/app/reducer.js b/webapp/src/context/app/reducer.js
new file mode 100644
index 0000000..cc1536a
--- /dev/null
+++ b/webapp/src/context/app/reducer.js
@@ -0,0 +1,16 @@
+export const reducer = (state, action) => {
+  switch (action.type) {
+
+    case "togglePolling":
+      return { ...state,
+        disablePolling: !state.disablePolling // on/off
+      }
+
+    default:
+      return state
+  }
+}
+
+export const initialState = {
+  disablePolling: false,
+}
diff --git a/webapp/src/context/data/Poll.js b/webapp/src/context/data/Poll.js
new file mode 100644
index 0000000..55b37cf
--- /dev/null
+++ b/webapp/src/context/data/Poll.js
@@ -0,0 +1,40 @@
+import { useState, useCallback, useEffect,  } from "react"
+
+export default function Poll(url, interval_sec, disabled) {
+    const [cache, setCache] = useState(null)
+    const [fetching, setFetching] = useState(false)
+    const [timeoutID, setTimeoutID] = useState(null)
+
+    const fecthData = useCallback(() => {
+        setTimeoutID(null)
+        setFetching(true)
+
+        fetch(url)
+            .then((response) => {
+                setFetching(false)
+                return response.json()
+            })
+            .then((freshData) => setCache(freshData))
+            .catch((err) => console.log(err.message))
+    }, [url])
+
+    useEffect(() => {
+        if (cache == null) {
+            fecthData()  // <<-- run immediatly on startup
+        }
+        else if (disabled === true) {
+            clearTimeout(timeoutID) // cancel already scheduled fetch
+            setTimeoutID(null)
+        }
+        else if (timeoutID === null) {
+            const timeoutID = setTimeout(fecthData, interval_sec * 1000)
+            setTimeoutID(timeoutID)
+            console.log("Fetch '" +url +"' scheduled in " +interval_sec +" sec")
+        }
+    }, [url, cache, fecthData, timeoutID, disabled, interval_sec]);
+
+    return {
+        data: cache,
+        fetching
+    }
+}
diff --git a/webapp/src/context/data/index.jsx b/webapp/src/context/data/index.jsx
new file mode 100644
index 0000000..c1dc614
--- /dev/null
+++ b/webapp/src/context/data/index.jsx
@@ -0,0 +1,36 @@
+import React from "react"
+import { reducer, initialState } from "./reducer"
+import { AppContext } from "../app"
+
+import Poll from "./Poll"
+
+export const AppData = React.createContext({
+  state: initialState,
+  dispatch: () => null
+})
+
+export const AppDataProvider = ({ children }) => {
+
+  const [data, dispatchData] = React.useReducer(reducer, initialState)
+  const [appContext] = React.useContext(AppContext)
+
+  const games = Poll('api/gamestate', 30, appContext.disablePolling)
+  const leaderboard = Poll('api/leaderboard', 60, appContext.disablePolling)
+  
+  data.games       = games.data
+  data.leaderboard = leaderboard.data
+  
+  var fetching = []
+  if (games.fetching === true)
+    fetching =  [...fetching, "games"]
+  if (leaderboard.fetching === true)
+    fetching =  [...fetching, "leaderboard"]
+  
+  data.fetching = fetching
+  
+  return (
+    <AppData.Provider value={[data, dispatchData]}>
+      {children}
+    </AppData.Provider>
+  )
+}
diff --git a/webapp/src/context/data/reducer.js b/webapp/src/context/data/reducer.js
new file mode 100644
index 0000000..b6fcb2e
--- /dev/null
+++ b/webapp/src/context/data/reducer.js
@@ -0,0 +1,14 @@
+export const reducer = (state, action) => {
+  switch (action.type) {
+
+    default:
+      console.warn("Unknown action.type", action)
+      return state
+  }
+}
+  
+export const initialState = { 
+  games: null,
+  leaderboard: null,
+  fetching: []
+}
diff --git a/webapp/src/index.js b/webapp/src/index.js
index d563c0f..58da36a 100644
--- a/webapp/src/index.js
+++ b/webapp/src/index.js
@@ -1,14 +1,21 @@
 import React from 'react';
 import ReactDOM from 'react-dom/client';
 import './index.css';
-import App from './App';
 import reportWebVitals from './reportWebVitals';
+import App from './App';
+import { AppDataProvider } from "./context/data"
+import { AppContextProvider } from "./context/app"
 
 const root = ReactDOM.createRoot(document.getElementById('root'));
 root.render(
-  <React.StrictMode>
-    <App />
-  </React.StrictMode>
+
+  //<React.StrictMode>
+  <AppContextProvider>
+    <AppDataProvider>
+      <App />
+    </AppDataProvider>
+  </AppContextProvider>
+  //</React.StrictMode>
 );
 
 // If you want to start measuring performance in your app, pass a function