diff --git a/Controller/ConfigController.php b/Controller/ConfigController.php
index 3c2bc3d..e118975 100644
--- a/Controller/ConfigController.php
+++ b/Controller/ConfigController.php
@@ -25,6 +25,8 @@ class ConfigController extends BaseController
                 'organon_tweaks_shortcut_labels' => (int) $this->configModel->get('organon_tweaks_shortcut_labels', 1),
                 'organon_tweaks_title_click_edit' => (int) $this->configModel->get('organon_tweaks_title_click_edit', 1),
                 'organon_tweaks_persistent_sort' => (int) $this->configModel->get('organon_tweaks_persistent_sort', 1),
+                'organon_tweaks_done_badge' => (int) $this->configModel->get('organon_tweaks_done_badge', 0),
+                'organon_tweaks_done_closes_task' => (int) $this->configModel->get('organon_tweaks_done_closes_task', 0),
             ),
             'errors' => array(),
         )));
@@ -45,6 +47,8 @@ class ConfigController extends BaseController
         $shortcutLabels = isset($values['organon_tweaks_shortcut_labels']) ? 1 : 0;
         $titleClickEdit = isset($values['organon_tweaks_title_click_edit']) ? 1 : 0;
         $persistentSort = isset($values['organon_tweaks_persistent_sort']) ? 1 : 0;
+        $doneBadge = isset($values['organon_tweaks_done_badge']) ? 1 : 0;
+        $doneClosesTask = isset($values['organon_tweaks_done_closes_task']) ? 1 : 0;
 
         if ($this->configModel->save(array(
             'organon_tweaks_always_comment_icon' => $alwaysCommentIcon,
@@ -58,6 +62,8 @@ class ConfigController extends BaseController
             'organon_tweaks_shortcut_labels' => $shortcutLabels,
             'organon_tweaks_title_click_edit' => $titleClickEdit,
             'organon_tweaks_persistent_sort' => $persistentSort,
+            'organon_tweaks_done_badge' => $doneBadge,
+            'organon_tweaks_done_closes_task' => $doneClosesTask,
         ))) {
             $this->flash->success(t('Settings saved successfully.'));
         } else {
diff --git a/Controller/DoneController.php b/Controller/DoneController.php
new file mode 100644
index 0000000..0f063a5
--- /dev/null
+++ b/Controller/DoneController.php
@@ -0,0 +1,47 @@
+<?php
+
+namespace Kanboard\Plugin\OrganonTweaks\Controller;
+
+use Kanboard\Controller\BaseController;
+use Kanboard\Plugin\OrganonTweaks\Helper\OrganonDoneHelper;
+
+/**
+ * Toggle a task's Done/Due badge (OrganonTweaks).
+ *
+ * One-click CSRF link from the board card face and the task view. Single source of truth per mode:
+ *   - close-mode on:  Done == closed, so this just closes/opens the task (no metadata); native
+ *     Close/Open stay in sync automatically because the badge reads is_active.
+ *   - close-mode off: this flips the 'organon_done' metadata marker and never touches open/closed.
+ * Redirects back to wherever it was clicked (board or task view).
+ */
+class DoneController extends BaseController
+{
+    public function toggle()
+    {
+        $task = $this->getTask();
+        $this->checkCSRFParam();
+
+        $helper = new OrganonDoneHelper($this->container);
+        $done = $helper->isDone($task);
+
+        if ($helper->closesTask()) {
+            if ($done) {
+                $this->taskStatusModel->open($task['id']);
+            } else {
+                $this->taskStatusModel->close($task['id']);
+            }
+        } else {
+            if ($done) {
+                $this->taskMetadataModel->remove($task['id'], OrganonDoneHelper::DONE_KEY);
+            } else {
+                $this->taskMetadataModel->save($task['id'], array(OrganonDoneHelper::DONE_KEY => 'on'));
+            }
+        }
+
+        if ($this->request->getStringParam('from') === 'board') {
+            $this->response->redirect($this->helper->url->to('BoardViewController', 'show', array('project_id' => $task['project_id'])), true);
+        } else {
+            $this->response->redirect($this->helper->url->to('TaskViewController', 'show', array('task_id' => $task['id'])), true);
+        }
+    }
+}
diff --git a/Helper/OrganonDoneHelper.php b/Helper/OrganonDoneHelper.php
new file mode 100644
index 0000000..b94c6b4
--- /dev/null
+++ b/Helper/OrganonDoneHelper.php
@@ -0,0 +1,50 @@
+<?php
+
+namespace Kanboard\Plugin\OrganonTweaks\Helper;
+
+use Kanboard\Core\Base;
+
+/**
+ * Done/Due badge helper.
+ *
+ * "Done" has a single source of truth PER MODE (no drift with native Close/Open):
+ *   - close-mode on  ("check done also closes tasks"): Done == the task is CLOSED (is_active == 0).
+ *     The badge reads the task's own is_active, so however a task is closed/reopened (badge, native
+ *     sidebar, bulk, API) the badge always matches. No metadata is stored in this mode.
+ *   - close-mode off (marker only): Done == the task metadata DONE_KEY == 'on', independent of the
+ *     open/closed status. Stored as the non-falsy string 'on' (never '0'/'1'): MetadataModel::get()
+ *     uses `?:` and PHP treats "0" as falsy, so a stored "0" would read back as the default.
+ *
+ * Templates cannot read models directly, so the board/task-view badge templates call isDone() here,
+ * passing the task array (which carries both id and is_active) so the close-mode read needs no query.
+ */
+class OrganonDoneHelper extends Base
+{
+    const DONE_KEY = 'organon_done';
+    const CLOSES_KEY = 'organon_tweaks_done_closes_task';
+
+    /**
+     * Is this task Done? (mode-aware: closed status in close-mode, else the metadata marker)
+     *
+     * @param  array $task  a task array carrying 'id' and 'is_active'
+     * @return bool
+     */
+    public function isDone(array $task)
+    {
+        if ($this->closesTask()) {
+            return isset($task['is_active']) && (int) $task['is_active'] === 0;
+        }
+
+        return $this->taskMetadataModel->get((int) $task['id'], self::DONE_KEY, '') === 'on';
+    }
+
+    /**
+     * Should toggling Done also close (and reopen) the task? Global setting, default off.
+     *
+     * @return bool
+     */
+    public function closesTask()
+    {
+        return (int) $this->configModel->get(self::CLOSES_KEY, 0) === 1;
+    }
+}
diff --git a/Plugin.php b/Plugin.php
index 896367f..6c2b9a9 100644
--- a/Plugin.php
+++ b/Plugin.php
@@ -111,6 +111,16 @@ class Plugin extends Base
             });
         }
 
+        // Tweak: a Done/Due status badge on the card face (top-right, below the header) and in the
+        // task view (4th column, near the due date). Two-state toggle; single source of truth per
+        // mode -- close-mode ON => Done == closed (reads is_active, so native Close/Open stay in
+        // sync); close-mode OFF => a task-metadata marker (organon_done). Server-rendered, no JS.
+        if ((int) $this->configModel->get('organon_tweaks_done_badge', 0) === 1) {
+            $this->template->hook->attach('template:board:private:task:before-title', 'organonTweaks:board/done_badge');
+            $this->template->hook->attach('template:task:details:fourth-column', 'organonTweaks:task/done_badge');
+            $this->template->hook->attach('template:layout:head', 'organonTweaks:layout/done_style');
+        }
+
         // Auto-managed shared custom filters (v1.5 "Show all tasks", v1.6 month filters, v1.7
         // recurring filters). Ensured lazily whenever a project header renders (covers old + new
         // boards); each group is gated by its own config toggle inside
@@ -141,7 +151,7 @@ class Plugin extends Base
     public function getHelpers()
     {
         return array(
-            'Plugin\OrganonTweaks\Helper' => array('OrganonColumnHelper', 'OrganonProjectHelper', 'OrganonSortHelper'),
+            'Plugin\OrganonTweaks\Helper' => array('OrganonColumnHelper', 'OrganonProjectHelper', 'OrganonSortHelper', 'OrganonDoneHelper'),
         );
     }
 
@@ -162,7 +172,7 @@ class Plugin extends Base
 
     public function getPluginVersion()
     {
-        return '1.9.1';
+        return '2.0.0';
     }
 
     public function getPluginHomepage()
diff --git a/README.md b/README.md
index 70aafe4..31cb9f6 100644
--- a/README.md
+++ b/README.md
@@ -117,6 +117,26 @@ single arrow** (up for ascending, down for descending) when it is ON.
   (which also hides the native sort menu). Per-column state lives in project metadata.
 - **On by default.** Toggle it under "Settings -> Organon Tweaks".
 
+### Done/Due badge
+
+A two-state toggle badge for marking a card done, shown on the board card face (top-right, below the
+header) and on the task view (4th column, near the due date). It reads **`[ ] Due`** (dark red) while
+the task is pending; one click flips it to **`[x] Done`** (light green). The card itself is not
+recolored -- only the badge. The "Due" colors reuse FinanceBuddy's debit badge for consistency.
+
+- Rendered server-side (no JavaScript) via `template:board:private:task:before-title`
+  (`Template/board/done_badge.php`), `template:task:details:fourth-column`
+  (`Template/task/done_badge.php`), and a small head `<style>` (`Template/layout/done_style.php`).
+  Shown only to users who may edit the task; on the board it appears on expanded (non-collapsed) cards.
+- **Single source of truth, no drift with native Close/Open.** With *"Marking Done also closes the
+  task"* **on**, "Done" *means* the task is closed: the badge reads the task's own open/closed status,
+  so closing or reopening a task by any route (the badge, the native sidebar, bulk actions, the API)
+  always keeps the badge correct. A closed "Done" card is hidden from the board by Kanboard's default
+  open-only filter, but reappears if you clear the filter (or use the "Board: show all tasks" filter).
+- With that option **off**, the badge is an independent marker stored in task metadata
+  (`organon_done`) that never touches the open/closed status.
+- **Off by default.** Toggle it under "Settings -> Organon Tweaks".
+
 ## Settings
 
 Global (per Kanboard instance) and admin-only, under "Settings -> Organon Tweaks", grouped as on
@@ -143,6 +163,11 @@ the page:
 
 - **Per-column persistent sort** -- default on.
 
+**Done badge**
+
+- **Show a Done/Due badge on cards** -- default off.
+- **Marking Done also closes the task** -- default off.
+
 Standalone:
 
 - **Keep the board scroll position across refreshes** -- default on.
diff --git a/Template/board/done_badge.php b/Template/board/done_badge.php
new file mode 100644
index 0000000..17fed4e
--- /dev/null
+++ b/Template/board/done_badge.php
@@ -0,0 +1,23 @@
+<?php
+/**
+ * Done/Due badge on the board card face. Rendered by template:board:private:task:before-title; the
+ * CSS in layout/done_style.php pins it to the top-right (below the header) and colors the two states.
+ * Only shown to users who may edit the task (a read-only viewer sees no badge). Expanded cards only
+ * (collapsed cards do not fire this hook).
+ */
+if (! $this->user->hasProjectAccess('TaskModificationController', 'edit', $task['project_id'])) {
+    return;
+}
+$done = $this->OrganonDoneHelper->isDone($task);
+?>
+<span class="organontweaks-done<?= $done ? ' is-done' : '' ?>">
+    <?= $this->url->link(
+        $done ? '<i class="fa fa-check-square fa-fw"></i> '.t('Done') : '<i class="fa fa-square-o fa-fw"></i> '.t('Due'),
+        'DoneController',
+        'toggle',
+        array('plugin' => 'OrganonTweaks', 'task_id' => $task['id'], 'project_id' => $task['project_id'], 'from' => 'board'),
+        true,
+        '',
+        $done ? t('Mark as not done') : t('Mark as done')
+    ) ?>
+</span>
diff --git a/Template/config/show.php b/Template/config/show.php
index 502d738..9a8aa33 100644
--- a/Template/config/show.php
+++ b/Template/config/show.php
@@ -62,6 +62,16 @@
         <p class="form-help"><?= t('Replaces the native column sort with a control that adds a number-aware Title sort and a "Persistent sort: ON/OFF" toggle. When ON, the column is re-sorted whenever a card is dropped in or created, so it stays sorted (a red up/down arrow marks it). OFF is the native one-shot sort.') ?></p>
     </fieldset>
 
+    <fieldset>
+        <legend><?= t('Done badge') ?></legend>
+
+        <?= $this->form->checkbox('organon_tweaks_done_badge', t('Show a Done/Due badge on cards'), 1, isset($values['organon_tweaks_done_badge']) && $values['organon_tweaks_done_badge'] == 1) ?>
+        <p class="form-help"><?= t('A two-state toggle badge on the board card (top-right) and the task view (near the due date): "Due" (red) until you click it, then "Done" (green). Off by default.') ?></p>
+
+        <?= $this->form->checkbox('organon_tweaks_done_closes_task', t('Marking Done also closes the task'), 1, isset($values['organon_tweaks_done_closes_task']) && $values['organon_tweaks_done_closes_task'] == 1) ?>
+        <p class="form-help"><?= t('When on, "Done" means the task is closed (so it leaves the board unless you clear the status filter), and clicking Due reopens it -- native Close/Open stay in sync. When off, the badge is an independent marker that never changes the open/closed status.') ?></p>
+    </fieldset>
+
     <div class="form-actions">
         <button type="submit" class="btn btn-blue"><?= t('Save') ?></button>
     </div>
diff --git a/Template/layout/done_style.php b/Template/layout/done_style.php
new file mode 100644
index 0000000..e4dc62a
--- /dev/null
+++ b/Template/layout/done_style.php
@@ -0,0 +1,33 @@
+<?php
+/**
+ * Done/Due badge styling (emitted into the head when the feature is enabled). Two states via
+ * .is-done. The Due colors reuse FinanceBuddy's debit badge (#b94a48 / white); Done is a light green
+ * with black font. On the board the badge is pinned top-right, below the header (the card .task-board
+ * is position:relative); the title reserves right padding so the badge does not cover it. In the task
+ * view it is a normal inline list item. Font size is inherited (0.9em on the board, matching the card
+ * id / assignee). All values are safe to tune.
+ */
+?>
+<style>
+.organontweaks-done a {
+    text-decoration: none;
+    padding: 0 5px;
+    border-radius: 3px;
+    background: #b94a48;
+    color: #fff;
+}
+.organontweaks-done.is-done a {
+    background: #a5d6a7;
+    color: #000;
+    font-weight: bold;
+}
+.task-board .organontweaks-done {
+    position: absolute;
+    top: 24px;
+    right: 5px;
+    z-index: 5;
+}
+.task-board .task-board-title {
+    padding-right: 4.2em;
+}
+</style>
diff --git a/Template/task/done_badge.php b/Template/task/done_badge.php
new file mode 100644
index 0000000..150d9ef
--- /dev/null
+++ b/Template/task/done_badge.php
@@ -0,0 +1,24 @@
+<?php
+/**
+ * Done/Due badge in the task view, 4th column (near the due date). Rendered by
+ * template:task:details:fourth-column as a list item, matching the surrounding <li> fields. Same
+ * two-state toggle as the board badge; only shown to users who may edit the task.
+ */
+if (! $this->user->hasProjectAccess('TaskModificationController', 'edit', $task['project_id'])) {
+    return;
+}
+$done = $this->OrganonDoneHelper->isDone($task);
+?>
+<li>
+    <span class="organontweaks-done<?= $done ? ' is-done' : '' ?>">
+        <?= $this->url->link(
+            $done ? '<i class="fa fa-check-square fa-fw"></i> '.t('Done') : '<i class="fa fa-square-o fa-fw"></i> '.t('Due'),
+            'DoneController',
+            'toggle',
+            array('plugin' => 'OrganonTweaks', 'task_id' => $task['id'], 'project_id' => $task['project_id'], 'from' => 'task'),
+            true,
+            '',
+            $done ? t('Mark as not done') : t('Mark as done')
+        ) ?>
+    </span>
+</li>
diff --git a/VERSION b/VERSION
index 6c2b60b..0d4322f 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-OrganonTweaks v1.9.1
+OrganonTweaks v2.0.0