diff --git a/index.js b/index.js
index 0ce35d5..f4c595e 100644
--- a/index.js
+++ b/index.js
@@ -10,32 +10,25 @@ let gController = null;
 						alert('assertion failed'); // eslint-disable-line no-alert
 					}
 				},
-				keys: theObject => {
-					const ret = [];
-					for (const aProperty in theObject) {
-						if (theObject.hasOwnProperty(aProperty)) { // eslint-disable-line no-prototype-builtins
-							ret.push(aProperty);
-						}
-					}
-
-					return ret;
+				keys(theObject) {
+					return Object.keys(theObject);
 				},
 				createElement(theTag, theProperties, theClassList) {
-					const ret = document.createElement(theTag);
+					const returnValue = document.createElement(theTag);
 					if ((typeof undefined !== typeof theProperties) && (theProperties !== null)) {
 						this.keys(theProperties).forEach(theProperty => {
-							ret[theProperty] = theProperties[theProperty];
+							returnValue[theProperty] = theProperties[theProperty];
 						});
 					}
 
 					if ((typeof undefined !== typeof theClassList) && (theClassList !== null)) {
 						theClassList.forEach(theClass => {
-							ret.classList.add(theClass);
+							returnValue.classList.add(theClass);
 						});
 					}
 
-					return ret;
-				}
+					return returnValue;
+				},
 			};
 
 			self.buttonDisable = function (theButton) {
@@ -49,7 +42,7 @@ let gController = null;
 			};
 
 			self.model = {
-				enabled: true
+				enabled: true,
 			};
 
 			self.show = function () {
@@ -60,12 +53,16 @@ let gController = null;
 				aDOMLink.append(aDOMHref);
 				const aAddress = '1ig1p1awfjS5bQxy2s33AD8sVspy4YFMD';
 				const aDOMBitcoin = self.util.createElement('div', {textContent: aAddress}, ['bitcoin']);
-				const aDOMQR = self.util.createElement('img', {src: aAddress + '.png', alt: aAddress, width: '200', height: '200'});
+				const aDOMQR = self.util.createElement('img', {
+					src: aAddress + '.png', alt: aAddress, width: '200', height: '200',
+				});
 				[aDOMLink, aDOMQR, aDOMBitcoin].forEach(theDOM => {
 					aDOMFooter.append(theDOM);
 				});
 
-				const aDOMInputSatoshiEuro = self.util.createElement('input', {type: 'text', value: '', maxlength: 30, size: 30}, ['input_text']);
+				const aDOMInputSatoshiEuro = self.util.createElement('input', {
+					type: 'text', value: '', maxlength: 30, size: 30,
+				}, ['input_text']);
 
 				const aDOMWrapResult = self.util.createElement('div', null, ['wrap-result']);
 				const aDOMLabelResult = self.util.createElement('span', {textContent: 'Result:'});
@@ -81,17 +78,17 @@ let gController = null;
 						if (self.model.enabled === true) {
 							self.model.enabled = false;
 							self.buttonDisable(aDOMButtonConvert);
-							aDOMValueResult.textContent = 100000000 / aDOMInputSatoshiEuro.value;
+							aDOMValueResult.textContent = 100_000_000 / aDOMInputSatoshiEuro.value;
 							setTimeout(() => {
 								self.buttonEnable(aDOMButtonConvert);
 								self.model.enabled = true;
 							}, 1000);
 						}
-					}
+					},
 				}, ['ig_button', 'normal']);
 
 				[
-					aDOMInputSatoshiEuro, aDOMButtonConvert, aDOMWrapResult, aDOMFooter
+					aDOMInputSatoshiEuro, aDOMButtonConvert, aDOMWrapResult, aDOMFooter,
 				].forEach(theDOM => {
 					aDOMContainer.append(theDOM);
 				});
diff --git a/package.json b/package.json
index 27fbc79..88e225b 100644
--- a/package.json
+++ b/package.json
@@ -3,12 +3,16 @@
 		"test": "xo"
 	},
 	"devDependencies": {
-		"xo": "^0.32.1"
+		"xo": "^0.58.0"
 	},
 	"xo": {
 		"esnext": true,
 		"space": false,
-		"rules": {},
+		"rules": {
+			"unicorn/no-array-for-each": 0,
+			"unicorn/prefer-module": 0,
+			"unicorn/no-this-assignment": 0
+		},
 		"semicolon": true,
 		"envs": [
 			"browser",
diff --git a/pm2-serve.sh b/pm2-serve.sh
new file mode 100644
index 0000000..1596c09
--- /dev/null
+++ b/pm2-serve.sh
@@ -0,0 +1 @@
+pm2 serve . 8081 --name satoshieuro-eurobitcoin_converter-8081