diff --git a/toys/convulse/convulse.js b/toys/convulse/convulse.js
index f7fc52a..6d52c17 100644
--- a/toys/convulse/convulse.js
+++ b/toys/convulse/convulse.js
@@ -35,8 +35,7 @@ class Convulse {
     
     document.querySelector("canvas").addEventListener("click", e => this.rec(e))
     document.querySelector("#rec").addEventListener("click", e => this.rec(e))
-    //document.querySelector("#save").addEventListener("click", e => this.save(e))
-    
+
     document.querySelector("#webcam-size").addEventListener("input", e => this.setWebcamSize(e))
     document.querySelector("#webcam-size").value = localStorage.webcamSize || 0.3
     document.querySelector("#webcam-size").dispatchEvent(new Event("input"))
@@ -51,19 +50,34 @@ class Convulse {
     
     this.recorder = {state: "unstarted"}
     
+    // this.mediaStream gets audio directly from the device, video from canvas
     this.mediaStream = new MediaStream()
     
-    navigator.mediaDevices.getUserMedia({video: true, audio: true})
-    .then(media => {
-      document.querySelector("#hello").classList.add("hidden")
-      this.webcamVideo.muted = true
-      this.webcamVideo.srcObject = media
-      this.webcamVideo.play()
-      for (let at of media.getAudioTracks()) {
-        this.mediaStream.addTrack(at)
-        console.log("Adding audio track", at)
+    // Populate select boxes with what media is available
+    navigator.mediaDevices.enumerateDevices()
+    .then(devs => {
+      for (let dev of devs) {
+        let opt = document.createElement("option")
+        opt.value = dev.deviceId
+        if (dev.kind == "audioinput") {
+          opt.text = dev.label || `Microphone ${aud.length+1}`
+          aud.appendChild(opt)
+        } else if (dev.kind == "videoinput") {
+          opt.text = dev.label || `Camera ${vid.length+1}`
+          vid.appendChild(opt)
+        }
       }
     })
+    
+    // Pretend the user clicked whatever's in those boxes
+    let aud = document.querySelector("#audio-in")
+    let vid = document.querySelector("#video-in")
+    aud.addEventListener("change", e => this.inputSelect(e))
+    vid.addEventListener("change", e => this.inputSelect(e))
+    this.inputSelect()
+    
+    navigator.mediaDevices.getUserMedia({video: true, audio: true})
+    .then(media => this.gotUserMedia(media))
     .catch(err => {
       toast("Couldn't open camera!")
     })
@@ -81,7 +95,6 @@ class Convulse {
     let canvasStream = this.canvas.captureStream(30)
     for (let vt of canvasStream.getVideoTracks()) {
       this.mediaStream.addTrack(vt)
-      console.log("Adding video track", vt)
     }
     
     this.frame()
@@ -89,6 +102,52 @@ class Convulse {
     toast("Click anywhere to start and stop recording")
   }
   
+  gotUserMedia(media) {
+    document.querySelector("#hello").classList.add("hidden")
+    
+    // Set video source
+    // sending this to an HTML element seems janky, is there no direct method for video?
+    if (this.webcamVideo.srcObject) {
+      for (let track of this.webcamVideo.srcObject.getTracks()) {
+        track.stop()
+      }
+    }
+    for (let track of media.getVideoTracks()) {
+      for (let opt of document.querySelector("#video-in")) {
+        if (opt.text == track.label) {
+          opt.selected = true
+        }
+      }
+    }
+    this.webcamVideo.muted = true
+    this.webcamVideo.srcObject = media
+    this.webcamVideo.play()
+    
+    // Set audio source
+    for (let track of this.mediaStream.getAudioTracks()) {
+      this.mediaStream.removeTrack(track)
+      track.stop()
+    }
+    for (let track of media.getAudioTracks()) {
+      this.mediaStream.addTrack(track)
+      for (let opt of document.querySelector("#audio-in")) {
+        opt.selected = (opt.value == track.deviceId)
+      }
+    }
+  }
+  
+  inputSelect(event) {
+    let audName = document.querySelector("#audio-in").value || undefined
+    let vidName = document.querySelector("#video-in").value || undefined
+    let constraints = {
+      audio: {deviceId: {exact: audName}},
+      video: {deviceId: {exact: vidName}}
+    }
+
+    navigator.mediaDevices.getUserMedia(constraints)
+    .then(e => this.gotUserMedia(e))
+  }
+  
   setWebcamSize(event) {
     this.webcamSize = event.target.value
     localStorage.webcamSize = this.webcamSize
diff --git a/toys/convulse/index.html b/toys/convulse/index.html
index 185e15d..5361e59 100644
--- a/toys/convulse/index.html
+++ b/toys/convulse/index.html
@@ -38,6 +38,10 @@
         <button id="rec">⏺️</button>
         <a id="save">💾</a>
       </div>
+      <div>
+        <span>🎙️<select id="audio-in"></select></span>
+        <span>🎥<select id="video-in"></select></span>
+      </div>
       <div id="webcam-controls">
         UR FACE
         <input id="webcam-size" type="range" min="0" max="1" step="0.01" value="0.2">
diff --git a/toys/convulse/sw.js b/toys/convulse/sw.js
index 9ec07c5..914523f 100644
--- a/toys/convulse/sw.js
+++ b/toys/convulse/sw.js
@@ -1,26 +1,51 @@
-var cacheName = "convulse-v1";
+// jshint asi:true
+
+var cacheName = "v2";
 var content = [
   "index.html",
   "convulse.css",
   "convulse.js",
   "convulse.png"
-];
+]
 
 
-self.addEventListener("install", e => {
-  e.waitUntil(caches.Open(cacheName).then(cache => cache.addAll(content)));
-});
+self.addEventListener("install", preCache)
+self.addEventListener("fetch", cachingFetch)
+self.addEventListener("activate", handleActivate)
 
-// Have mercy, this is a horror show
-self.addEventListener("fetch", e => {
-  e.respondWith(
-    caches.match(e.request).then(r => {
-      return r || fetch(e.request).then(response => {
-        return caches.open(cacheName).then(cache => {
-          cache.put(e.request, response.clone());
-          return response;
-        });
-      });
+function handleActivate(event){
+  event.waitUntil(
+    cleanup()
+  )
+}
+
+async function cleanup(event) {
+  let cacheNames = await caches.keys()
+  for (let name of cacheNames) {
+    if (name != cacheName) {
+      console.log("Deleting old cache", name)
+      caches.delete(name)
+    }
+  }
+}
+
+function preCache(event) {
+  event.waitUntil(
+    caches.open(cacheName)
+    .then(cache => cache.addAll(content))
+  )
+}
+
+// Go try to pull a newer version from the network,
+// but return what's in the cache for this request
+function cachingFetch(event) {
+  fetch(event.request)
+  .then(resp => {
+    caches.open(cacheName)
+    .then(cache => {
+      cache.put(event.request, resp.clone())
     })
-  );
-});
+  })
+  
+  event.respondWith(caches.match(event.request))
+}