diff --git a/ext/bg/js/translator.js b/ext/bg/js/translator.js
index 2331bde7..e534e0cb 100644
--- a/ext/bg/js/translator.js
+++ b/ext/bg/js/translator.js
@@ -54,10 +54,10 @@ class Translator {
                     percent += banks[url].loaded / banks[url].total;
                 }
 
-                percent /= 3;
+                percent /= 3.0;
 
                 if (callback) {
-                    callback({state: 'update', progress: Math.ceil(100 * percent)});
+                    callback({state: 'update', progress: Math.ceil(100.0 * percent)});
                 }
             };
 
@@ -69,7 +69,7 @@ class Translator {
                 return this.dictionary.sealDb();
             }).then(() => {
                 if (callback) {
-                    callback({state: 'end', progress: 100});
+                    callback({state: 'end', progress: 100.0});
                 }
             });
         }).then(() => {
diff --git a/ext/fg/js/client.js b/ext/fg/js/client.js
index daeabf99..717b5873 100644
--- a/ext/fg/js/client.js
+++ b/ext/fg/js/client.js
@@ -116,7 +116,7 @@ class Client {
                     return canAddDefinitions(definitions, ['term_kanji', 'term_kana']);
                 }).then(states => {
                     if (states !== null) {
-                        states.forEach((state, index) => this.popup.sendMessage('setActionState', {index, state, sequence }));
+                        states.forEach((state, index) => this.popup.invokeApi('setActionState', {index, state, sequence}));
                     }
                 });
             }
@@ -158,7 +158,7 @@ class Client {
         const state = {[mode]: false};
         addDefinition(this.definitions[index], mode).then(success => {
             if (success) {
-                this.popup.sendMessage('setActionState', {index, state, sequence: this.sequence});
+                this.popup.invokeApi('setActionState', {index, state, sequence: this.sequence});
             } else {
                 alert('Note could not be added');
             }
@@ -195,7 +195,7 @@ class Client {
                 return canAddDefinitions(definitions, ['kanji']);
             }).then(states => {
                 if (states !== null) {
-                    states.forEach((state, index) => this.popup.sendMessage('setActionState', {index, state, sequence}));
+                    states.forEach((state, index) => this.popup.invokeApi('setActionState', {index, state, sequence}));
                 }
             });
         });
diff --git a/ext/fg/js/frame.js b/ext/fg/js/frame.js
index 590646d5..8a99a405 100644
--- a/ext/fg/js/frame.js
+++ b/ext/fg/js/frame.js
@@ -17,11 +17,15 @@
  */
 
 
+function invokeApi(action, params, target) {
+    target.postMessage({action, params}, '*');
+}
+
 function registerKanjiLinks() {
     for (const link of Array.from(document.getElementsByClassName('kanji-link'))) {
         link.addEventListener('click', e => {
             e.preventDefault();
-            window.parent.postMessage({action: 'displayKanji', params: e.target.innerHTML}, '*');
+            invokeApi('displayKanji', e.target.innerHTML, window.parent);
         });
     }
 }
@@ -31,7 +35,7 @@ function registerAddNoteLinks() {
         link.addEventListener('click', e => {
             e.preventDefault();
             const ds = e.currentTarget.dataset;
-            window.parent.postMessage({action: 'addNote', params: {index: ds.index, mode: ds.mode}}, '*');
+            invokeApi('addNote', {index: ds.index, mode: ds.mode}, window.parent);
         });
     }
 }
@@ -41,7 +45,7 @@ function registerAudioLinks() {
         link.addEventListener('click', e => {
             e.preventDefault();
             const ds = e.currentTarget.dataset;
-            window.parent.postMessage({action: 'playAudio', params: ds.index}, '*');
+            invokeApi('playAudio', ds.index, window.parent);
         });
     }
 }
diff --git a/ext/fg/js/popup.js b/ext/fg/js/popup.js
index 930df18d..88b8e4e3 100644
--- a/ext/fg/js/popup.js
+++ b/ext/fg/js/popup.js
@@ -68,7 +68,7 @@ class Popup {
         doc.close();
     }
 
-    sendMessage(action, params, callback) {
+    invokeApi(action, params) {
         if (this.popup !== null) {
             this.popup.contentWindow.postMessage({action, params}, '*');
         }
diff --git a/ext/fg/js/util.js b/ext/fg/js/util.js
index 176765fc..c24ad885 100644
--- a/ext/fg/js/util.js
+++ b/ext/fg/js/util.js
@@ -17,28 +17,28 @@
  */
 
 
-function sendMessage(action, params) {
+function invokeApiBg(action, params) {
     return new Promise((resolve, reject) => chrome.runtime.sendMessage({action, params}, resolve));
 }
 
 function findTerm(text) {
-    return sendMessage('findTerm', {text});
+    return invokeApiBg('findTerm', {text});
 }
 
 function findKanji(text) {
-    return sendMessage('findKanji', {text});
+    return invokeApiBg('findKanji', {text});
 }
 
 function renderText(data, template) {
-    return sendMessage('renderText', {data, template});
+    return invokeApiBg('renderText', {data, template});
 }
 
 function canAddDefinitions(definitions, modes) {
-    return sendMessage('canAddDefinitions', {definitions, modes});
+    return invokeApiBg('canAddDefinitions', {definitions, modes});
 }
 
 function addDefinition(definition, mode) {
-    return sendMessage('addDefinition', {definition, mode});
+    return invokeApiBg('addDefinition', {definition, mode});
 }
 
 function textSourceFromPoint(point) {