diff --git a/src/client/scripts/app.js b/src/client/scripts/app.js
index f3565a0..3f01710 100644
--- a/src/client/scripts/app.js
+++ b/src/client/scripts/app.js
@@ -132,7 +132,7 @@ class App {
         this._videoPlayer.updateOfflineProgress(0, true);
       });
     }, err => {
-      console.log(err);
+      console.error("Video player init err:", err);
     });
   }
 
@@ -392,7 +392,7 @@ class App {
           Toast.create('Caching video for offline.', {tag: 'offline'});
           return this._offlineCache.add(name, assetPath, pagePath, drmInfo)
               .catch(_ => {
-                console.error(_);
+                console.error("OfflineCache add:", _);
                 Toast.create('Cancelled download.', {tag: 'offline'});
                 this._offlineDownloadState = App.VIDEO_DOWNLOAD_STATES.IDLE;
               });
diff --git a/src/client/scripts/background-fetch-helper.js b/src/client/scripts/background-fetch-helper.js
index 0dd5fb9..6b56b42 100644
--- a/src/client/scripts/background-fetch-helper.js
+++ b/src/client/scripts/background-fetch-helper.js
@@ -67,7 +67,7 @@ class BackgroundFetchHelper {
         return;
       }
 
-      console.log(assets);
+      console.log("Assets:", assets);
 
       return caches.open(id).then(cache => {
         const fetches = evt.fetches;
diff --git a/src/client/scripts/helpers/offline-cache.js b/src/client/scripts/helpers/offline-cache.js
index 106b12b..8f9e1da 100644
--- a/src/client/scripts/helpers/offline-cache.js
+++ b/src/client/scripts/helpers/offline-cache.js
@@ -183,7 +183,7 @@ class OfflineCache {
 
   add (name, assetPath, pagePath, drmInfo) {
     if (!Constants.SUPPORTS_CACHING) {
-      return;
+      return Promise.reject(new Error("does not support caching"));
     }
 
     const assets = [];
@@ -346,7 +346,7 @@ class OfflineCache {
 
             return this._downloadForeground('prefetch', fetches)
                 .catch(e => {
-                  console.error(e);
+                  console.error("DownloadForeground prefetch", e);
                 });
           })
           .catch(prefetchErr => {
diff --git a/src/client/scripts/helpers/service-worker-installer.js b/src/client/scripts/helpers/service-worker-installer.js
index e14e479..eb24e97 100644
--- a/src/client/scripts/helpers/service-worker-installer.js
+++ b/src/client/scripts/helpers/service-worker-installer.js
@@ -77,7 +77,7 @@ class ServiceWorkerInstaller {
         };
       };
     }, function (err) {
-      console.warn(err);
+      console.warn("Service worker registration unsuccessful:", err);
     });
   }
 }
diff --git a/src/client/scripts/ranged-response.js b/src/client/scripts/ranged-response.js
index ef7d6de..b50210a 100644
--- a/src/client/scripts/ranged-response.js
+++ b/src/client/scripts/ranged-response.js
@@ -294,7 +294,7 @@ class RangedResponse {
                 start, end, offset);
           });
     } catch (e) {
-      console.log(e);
+      console.error("RangedResponses cachedResponses:", e);
       return new Response(e.message, {status: 400});
     };
   }
diff --git a/src/client/scripts/video-player/video-player.js b/src/client/scripts/video-player/video-player.js
index aaad996..6eaa626 100644
--- a/src/client/scripts/video-player/video-player.js
+++ b/src/client/scripts/video-player/video-player.js
@@ -408,7 +408,7 @@ class VideoPlayer {
 
       // Lock the player to the offline stream.
       const tracks = this._player.getTracks().filter(t => {
-        console.log(t);
+        console.log("Track:", t);
         return t.height === Constants.PREFETCH_VIDEO_HEIGHT;
       });
 
@@ -525,7 +525,7 @@ class VideoPlayer {
   }
 
   _startChromecastWatch () {
-    console.log('_startChromecastWatch');
+    console.log('StartChromecastWatch');
     if (!VideoPlayer.SUPPORTS_REMOTE_PLAYBACK) {
       this._videoControls.hideChromecastButton();
       return;
@@ -533,7 +533,7 @@ class VideoPlayer {
 
     this._castVideo.src = this._castSrc;
     this._castVideo.remote.watchAvailability(available => {
-      console.log('_startChromecastWatch:' + available);
+      console.log('StartChromecastWatch:' + available);
       if (available) {
         this._videoControls.showChromecastButton();
         return;
@@ -619,7 +619,7 @@ class VideoPlayer {
     this._video.play().then(_ => {
       this._updateVideoControlsWithPlayerState();
     }, err => {
-      console.warn(err);
+      console.warn("OnPlay:", err);
     });
   }
 
@@ -749,17 +749,17 @@ class VideoPlayer {
   }
 
   _onRemoteConnect () {
-    console.log('_onRemoteConnect');
+    console.log('OnRemoteConnect');
     this._videoControls.castConnected = true;
   }
 
   _onRemoteConnecting () {
-    console.log('_onRemoteConnecting');
+    console.log('OnRemoteConnecting');
     this._videoControls.castConnecting = true;
   }
 
   _onRemoteDisconnect () {
-    console.log('_onRemoteDisconnect');
+    console.log('OnRemoteDisconnect');
     this._videoControls.castConnected = false;
   }