diff --git a/Readme.md b/Readme.md
index e558be6..e6f1973 100644
--- a/Readme.md
+++ b/Readme.md
@@ -4,6 +4,8 @@
 
 **Webbasiertes WLAN-Voucher-Management für UniFi OS** – mit Multi-Site-Support, Benutzerverwaltung, Microsoft-365-Login und integriertem Auto-Updater.
 
+Entwickelt von **[Loheide.eu](https://loheide.eu)**
+
 ![PHP](https://img.shields.io/badge/PHP-7.4%2B-777BB4?logo=php&logoColor=white)
 ![MySQL](https://img.shields.io/badge/MySQL-5.7%2B%20%2F%20MariaDB-4479A1?logo=mysql&logoColor=white)
 ![UniFi OS](https://img.shields.io/badge/UniFi%20OS-7.0%2B-0559C9?logo=ubiquiti&logoColor=white)
@@ -541,4 +543,6 @@ vendor/bin/phpstan analyse
 
 **Version 2.6.0** · Autor: **Friederich Loheide** · Lizenz: **MIT**
 
+Entwickelt von **[Loheide.eu](https://loheide.eu)**
+
 </div>
diff --git a/assets/global.css b/assets/global.css
index 49fe976..ce41678 100644
--- a/assets/global.css
+++ b/assets/global.css
@@ -1535,6 +1535,20 @@ input.search-bar, .site-selector .search-bar { min-width: 240px; width: auto; fl
 .print-qr { display: flex; justify-content: center; line-height: 0; }
 .print-qr img, .print-qr canvas { display: block; }
 
+/* Entwicklerhinweis im Seitenfuß */
+.app-credit {
+    margin: 0;
+    font-size: 11.5px;
+    color: var(--text-muted);
+}
+.app-credit a { color: var(--text-secondary); text-decoration: none; }
+.app-credit a:hover { color: var(--accent); text-decoration: underline; }
+.sidebar-foot .app-credit { margin-top: 10px; padding: 0 4px; text-align: center; }
+.app-footer { max-width: 560px; margin: 20px auto 0; text-align: center; }
+.login-container .app-credit { margin-top: 26px; text-align: center; }
+.focus-card .app-credit { margin-top: 22px; text-align: center; }
+.wrap .app-credit { margin-top: 18px; text-align: center; }
+
 /* Sprungmarke zum Inhalt (nur bei Tastaturfokus sichtbar) */
 .skip-link {
     position: absolute;
diff --git a/docs/screenshots/admin-dashboard-dark.png b/docs/screenshots/admin-dashboard-dark.png
index f41ea94..b615914 100644
Binary files a/docs/screenshots/admin-dashboard-dark.png and b/docs/screenshots/admin-dashboard-dark.png differ
diff --git a/docs/screenshots/admin-dashboard.png b/docs/screenshots/admin-dashboard.png
index 60d8402..bfb3012 100644
Binary files a/docs/screenshots/admin-dashboard.png and b/docs/screenshots/admin-dashboard.png differ
diff --git a/docs/screenshots/api-keys.png b/docs/screenshots/api-keys.png
index 73d2f00..98e3dd0 100644
Binary files a/docs/screenshots/api-keys.png and b/docs/screenshots/api-keys.png differ
diff --git a/docs/screenshots/bulk-vouchers.png b/docs/screenshots/bulk-vouchers.png
index e8252cd..4ceb658 100644
Binary files a/docs/screenshots/bulk-vouchers.png and b/docs/screenshots/bulk-vouchers.png differ
diff --git a/docs/screenshots/integrations.png b/docs/screenshots/integrations.png
index 7d68b10..41fb539 100644
Binary files a/docs/screenshots/integrations.png and b/docs/screenshots/integrations.png differ
diff --git a/docs/screenshots/login-branding.png b/docs/screenshots/login-branding.png
index 56eb3f0..799d8a9 100644
Binary files a/docs/screenshots/login-branding.png and b/docs/screenshots/login-branding.png differ
diff --git a/docs/screenshots/login.png b/docs/screenshots/login.png
index fcab8a3..133e8f0 100644
Binary files a/docs/screenshots/login.png and b/docs/screenshots/login.png differ
diff --git a/docs/screenshots/maintenance.png b/docs/screenshots/maintenance.png
index 52a70b7..55d6e4d 100644
Binary files a/docs/screenshots/maintenance.png and b/docs/screenshots/maintenance.png differ
diff --git a/docs/screenshots/settings-branding.png b/docs/screenshots/settings-branding.png
index 5e5d511..cec6e04 100644
Binary files a/docs/screenshots/settings-branding.png and b/docs/screenshots/settings-branding.png differ
diff --git a/docs/screenshots/settings-login.png b/docs/screenshots/settings-login.png
index 5a110cb..3c7d00f 100644
Binary files a/docs/screenshots/settings-login.png and b/docs/screenshots/settings-login.png differ
diff --git a/docs/screenshots/settings.png b/docs/screenshots/settings.png
index 688a9ee..cb6f489 100644
Binary files a/docs/screenshots/settings.png and b/docs/screenshots/settings.png differ
diff --git a/docs/screenshots/two-factor.png b/docs/screenshots/two-factor.png
index f85ddb6..7d9704b 100644
Binary files a/docs/screenshots/two-factor.png and b/docs/screenshots/two-factor.png differ
diff --git a/docs/screenshots/updater-available.png b/docs/screenshots/updater-available.png
index 0e3fec4..1ee6cd6 100644
Binary files a/docs/screenshots/updater-available.png and b/docs/screenshots/updater-available.png differ
diff --git a/docs/screenshots/updater.png b/docs/screenshots/updater.png
index 0e3fec4..1ee6cd6 100644
Binary files a/docs/screenshots/updater.png and b/docs/screenshots/updater.png differ
diff --git a/docs/screenshots/vouchers.png b/docs/screenshots/vouchers.png
index fb0e301..230dc97 100644
Binary files a/docs/screenshots/vouchers.png and b/docs/screenshots/vouchers.png differ
diff --git a/includes/Ui.php b/includes/Ui.php
index c2d3815..40bff32 100644
--- a/includes/Ui.php
+++ b/includes/Ui.php
@@ -116,6 +116,22 @@ class Ui
             . '</style>';
     }
 
+    /** Entwicklerhinweis – bewusst an einer Stelle gepflegt. */
+    public const CREDIT_NAME = 'Loheide.eu';
+    public const CREDIT_URL  = 'https://loheide.eu';
+
+    /**
+     * Dezenter Hinweis auf den Entwickler, wie er im Seitenfuß erscheint.
+     */
+    public static function credit(): string
+    {
+        $label = function_exists('__') ? __('credit_by') : 'Entwickelt von';
+
+        return '<p class="app-credit">' . htmlspecialchars($label) . ' '
+            . '<a href="' . self::CREDIT_URL . '" target="_blank" rel="noopener">'
+            . self::CREDIT_NAME . '</a></p>';
+    }
+
     /**
      * Standard-Druckvorlage (wird nur verwendet, solange keine eigene
      * Vorlage gespeichert ist). {QR_CODE} fuellt der Browser.
diff --git a/includes/admin_nav.php b/includes/admin_nav.php
index 4b5b099..6d4b671 100644
--- a/includes/admin_nav.php
+++ b/includes/admin_nav.php
@@ -76,8 +76,8 @@ foreach ($navGroups as $items) {
         <?php endforeach; ?>
     </nav>
 
-    <?php if ($currentUser): ?>
     <div class="sidebar-foot">
+        <?php if ($currentUser): ?>
         <div class="user-menu" style="width:100%;justify-content:flex-start;">
             <div class="user-avatar"><?= strtoupper(mb_substr($currentUser['name'], 0, 1)) ?></div>
             <div style="min-width:0;flex:1;">
@@ -88,8 +88,9 @@ foreach ($navGroups as $items) {
                 <i class="fas fa-arrow-right-from-bracket" aria-hidden="true"></i>
             </a>
         </div>
+        <?php endif; ?>
+        <?= Ui::credit() ?>
     </div>
-    <?php endif; ?>
 </aside>
 
 <header class="topbar">
diff --git a/index.php b/index.php
index 2ff5177..5b0b516 100644
--- a/index.php
+++ b/index.php
@@ -635,6 +635,8 @@ function buildPrintCard($template, $data, $instructionHeader, $instructionText,
     <?php endif; ?>
 </main>
 
+<footer class="app-footer no-print"><?= Ui::credit() ?></footer>
+
 <div id="toast-container" role="status" aria-live="polite"></div>
 <script src="assets/global.js"></script>
 <script>
diff --git a/install.php b/install.php
index 0c751ba..679f6f1 100644
--- a/install.php
+++ b/install.php
@@ -375,6 +375,7 @@ if ($step === 5 && $_SERVER['REQUEST_METHOD'] === 'POST') {
                 <button type="submit" class="btn btn-primary btn-lg btn-block">Installation abschließen</button>
             </form>
         <?php endif; ?>
+        <?= Ui::credit() ?>
     </div>
 </body>
 </html>
\ No newline at end of file
diff --git a/lang/de.php b/lang/de.php
index cd71885..3a84eab 100644
--- a/lang/de.php
+++ b/lang/de.php
@@ -469,6 +469,7 @@ return [
     'settings_qr_hint'             => '{QR_CODE} fügt einen QR-Code mit dem Voucher-Code ein.',
     'print_valid_until'            => 'Gültig bis',
     'print_devices'                => 'Geräte',
+    'credit_by'                    => 'Entwickelt von',
     'settings_tab_general'  => 'Allgemein',
     'settings_tab_defaults' => 'Voucher-Standards',
     'settings_tab_cron'     => 'Cron-Sync',
diff --git a/lang/en.php b/lang/en.php
index b5a6797..7a0ee39 100644
--- a/lang/en.php
+++ b/lang/en.php
@@ -469,6 +469,7 @@ return [
     'settings_qr_hint'             => '{QR_CODE} inserts a QR code containing the voucher code.',
     'print_valid_until'            => 'Valid until',
     'print_devices'                => 'devices',
+    'credit_by'                    => 'Developed by',
     'settings_tab_general'  => 'General',
     'settings_tab_defaults' => 'Voucher Defaults',
     'settings_tab_cron'     => 'Cron Sync',
diff --git a/login.php b/login.php
index 195d4d6..ccc325d 100644
--- a/login.php
+++ b/login.php
@@ -288,6 +288,7 @@ try {
     <?php if ($publicAccess): ?>
         <div class="auth-links"><a href="index.php" class="back-link"><i class="fas fa-arrow-left" aria-hidden="true"></i> <?= __('login_back') ?></a></div>
     <?php endif; ?>
+    <?= Ui::credit() ?>
 </div>
 </section>
 
diff --git a/updater/templates/maintenance.html b/updater/templates/maintenance.html
index 6f08e4a..a1c7502 100644
--- a/updater/templates/maintenance.html
+++ b/updater/templates/maintenance.html
@@ -90,6 +90,7 @@
         <p>Es wird gerade ein Update eingespielt. Die Seite ist in wenigen Augenblicken wieder erreichbar.</p>
         <div class="bar"></div>
         <p class="hint">Diese Seite aktualisiert sich automatisch.</p>
+        <p class="hint" style="margin-top:10px;">Entwickelt von <a href="https://loheide.eu" style="color:inherit;">Loheide.eu</a></p>
     </div>
 </body>
 </html>
diff --git a/updater/templates/update.php b/updater/templates/update.php
index 064ccdc..8c3c139 100644
--- a/updater/templates/update.php
+++ b/updater/templates/update.php
@@ -116,6 +116,7 @@ $channels = \Updater\UpdateManager::CHANNELS;
             <div class="alert alert-ok" id="migAlert"></div>
         </div>
     </div>
+    <?= Ui::credit() ?>
 </div>
 
 <script>