diff --git a/spago.dhall b/spago.dhall
index 74eb1a7..ddf3b2e 100644
--- a/spago.dhall
+++ b/spago.dhall
@@ -14,6 +14,7 @@
   , "effect"
   , "either"
   , "exceptions"
+  , "foldable-traversable"
   , "foreign"
   , "generic-parser"
   , "halogen"
diff --git a/src/App/Container.js b/src/App/Container.js
new file mode 100644
index 0000000..d84714d
--- /dev/null
+++ b/src/App/Container.js
@@ -0,0 +1,15 @@
+// Sets some raw HTML into a page given an element.
+// In the Halogen code, the parameter is of type `Web.HTML.HTMLElement`.
+//
+// Function signature: Web.HTML.HTMLElement -> RawHTML -> Effect Unit
+//
+// `RawHTML` is just a wrapper around a `String`. Nothing fancy.
+//
+// newtype RawHTML = RawHTML String
+export function unsafeSetInnerHTML(element) {
+  return function (html) {
+    return function () {
+      element.innerHTML = html;
+    };
+  };
+}
diff --git a/src/App/Container.purs b/src/App/Container.purs
index 7c2a93e..9350c22 100644
--- a/src/App/Container.purs
+++ b/src/App/Container.purs
@@ -50,15 +50,18 @@ import Prelude (Unit, bind, discard, unit, ($), (=<<), (<>), show, pure, (+), (&
 import Bulma as Bulma
 
 import Data.Array as A
-import Data.Maybe (Maybe(..), maybe)
+import Data.ArrayBuffer.Types (ArrayBuffer)
 import Data.Either (Either(..))
+import Data.Foldable (for_)
+import Data.Maybe (Maybe(..), maybe)
 import Data.Tuple (Tuple(..))
+import Effect.Aff.Class (class MonadAff)
+import Effect (Effect)
 import Halogen as H
 import Halogen.HTML as HH
 import Halogen.HTML.Properties as HP
 import Type.Proxy (Proxy(..))
-import Effect.Aff.Class (class MonadAff)
-import Data.ArrayBuffer.Types (ArrayBuffer)
+import Web.HTML (HTMLElement)
 
 import App.Message.DNSManagerDaemon as DNSManager
 import App.Message.AuthenticationDaemon as AuthD
@@ -96,6 +99,12 @@ type Login = String
 type Password = String
 type LogInfo = Tuple Login Password
 
+newtype RawHTML = RawHTML String
+
+-- | Since Halogen doesn't have a function to put raw HTML into a page, we have to improvise.
+-- | This foreign function adds raw HTML into a page, given a parent node reference.
+foreign import unsafeSetInnerHTML :: HTMLElement -> RawHTML -> Effect Unit
+
 -- | A keepalive message is sent every 30 seconds to keep the connection open.
 -- | `max_keepalive` represents the maximum number of keepalive messages
 -- | before closing the connections due to inactivity.
@@ -282,10 +291,19 @@ render state
     -- The footer includes logs and both the WS child components.
     , Bulma.hr
     , Bulma.columns_ [ Bulma.column_ [ Bulma.h3 "Logs (watch this if something fails 😅)", render_logs ]
-                     , Bulma.column_ [ Bulma.level [render_auth_WS, render_dnsmanager_WS, legal_notice_btn] [] ]
+                     , Bulma.column_ [ Bulma.level
+                       [ render_auth_WS
+                       , render_dnsmanager_WS
+                       , legal_notice_btn
+                       , paypal_btn
+                       ] [] ]
                      ]
     ]
   where
+
+    paypal_btn :: forall w i. HH.HTML w i
+    paypal_btn = HH.div [ HP.ref ref_paypal_div ] []
+
     legal_notice_btn = Bulma.btn_ [] "Legal notice" (Routing LegalNotice)
     reconnection_bar :: forall w. HH.HTML w Action
     reconnection_bar =
@@ -348,6 +366,9 @@ render state
     render_logs :: forall monad. MonadAff monad => H.ComponentHTML Action ChildSlots monad
     render_logs = Bulma.container [ HH.slot_ _log unit AppLog.component unit ]
 
+ref_paypal_div :: H.RefLabel
+ref_paypal_div = H.RefLabel "paypal-div"
+
 handleAction :: forall o monad. MonadAff monad => Action -> H.HalogenM State Action ChildSlots o monad Unit
 handleAction = case _ of
   Initialize -> do
@@ -364,6 +385,21 @@ handleAction = case _ of
       Just name -> do H.modify_ _ { login = Just name }
                       H.tell _nav unit $ NavigationInterface.TellLogin (Just name)
 
+    -- Render the paypal button.
+    -- How it works: it takes all nodes in the DOM with the reference `ref_paypal_div` ("paypal-div")
+    -- then it replaces the inner HTML by the provided code.
+    parentElem <- H.getHTMLElementRef ref_paypal_div
+    for_ parentElem \el -> do
+      H.liftEffect $ unsafeSetInnerHTML el (RawHTML """
+        <form action="https://www.paypal.com/donate" method="post" target="_blank">
+          <input type="hidden" name="business" value="YBYNZTGHQK5VA" />
+          <input type="hidden" name="no_recurring" value="0" />
+          <input type="hidden" name="currency_code" value="EUR" />
+          <input type="image" src="https://www.paypalobjects.com/en_US/i/btn/btn_donate_LG.gif" border="0" name="submit" title="PayPal - The safer, easier way to pay online!" alt="Donate with PayPal button" />
+          <img alt="" border="0" src="https://www.paypal.com/en_FR/i/scr/pixel.gif" width="1" height="1" />
+        </form>
+        """)
+
   Routing page -> do
     -- Each time the user change load a new page, the counter gets reset
     -- since it proves they are still active.