diff --git a/app.js b/app.js
index 98626d1..2716443 100644
--- a/app.js
+++ b/app.js
@@ -4,6 +4,13 @@ class Setup {
         const p = document.createElement("p")
         p.innerText = this.serviceWorkerStatus
         document.body.appendChild(p)
+        this.statusEl = p
+        const btn = document.createElement('button')
+        btn.addEventListener('click', () => this.unregister())
+        btn.innerText = 'unregister'
+        const p2 = document.createElement('p')
+        document.body.appendChild(p2)
+        p2.appendChild(btn)
     }
 
     async register() {
@@ -31,6 +38,27 @@ class Setup {
             console.error("serviceWorker not available")
         }
     }
+
+    async unregister() {
+        if ('serviceWorker' in navigator) {
+            try {
+                const regs = await navigator.serviceWorker.getRegistrations()
+                const res = await Promise.allSettled(
+                    regs.map(reg => reg.unregister())
+                )
+                this.serviceWorkerStatus = (
+                    res.every(pr => pr.status === 'fulfilled') ?
+                    'unregistered' :
+                    'error'
+                )
+            } catch (err) {
+                console.error("error in unregister", err)
+            }
+        } else {
+            this.serviceWorkerStatus = 'unavailable'
+        }
+        this.statusEl.innerText = this.serviceWorkerStatus
+    }
 }
 
 new Setup().run()
\ No newline at end of file