diff --git a/.github/ISSUE_TEMPLATE.md b/.github/ISSUE_TEMPLATE.md
new file mode 100644
index 0000000..91c5032
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE.md
@@ -0,0 +1,3 @@
+###### 下記の問題を説明してください。 スクリーンショットと診断情報を含めてください。
+###### Describe the problem you are having below. Please include a screenshot and the diagnostic information.
+
diff --git a/public/src/css/main.css b/public/src/css/main.css
index b91867a..c188c95 100644
--- a/public/src/css/main.css
+++ b/public/src/css/main.css
@@ -12,8 +12,10 @@ body{
 	width: 100%;
 	height: 100%;
 	background: #fe7839;
+	position: absolute;
 	user-select: none;
 	touch-action: none;
+	overflow: hidden;
 }
 #screen{
 	width: 100%;
@@ -135,30 +137,34 @@ body{
 #tutorial{
 	background: rgb(246, 234, 212);
 	color: black;
-	border: 5px black solid;
-	border-radius: 10px;
-	height: 65%;
-	max-width: 800px;
-	padding: 20px;
-	margin: 8px;
-	font-size: 16pt;
+	border: 0.25em black solid;
+	border-radius: 0.5em;
+	width: 800px;
+	padding: 1em;
+	margin: 1em;
+	font-size: 21px;
 	position: relative;
 }
+.touch-enabled #tutorial{
+	font-size: 3vmin;
+}
 #tutorial-title{
 	z-index: 1;
 	position: absolute;
 	color: white;
-	top: -25px;
-	font-size: 26pt;
+	top: -0.7em;
+	font-size: 1.65em;
 }
 #tutorial-content{
-	padding: 15px 30px;
+	margin: 0.7em 0;
+	overflow-y: auto;
+	max-height: calc(100vh - 14em);
 }
 kbd{
 	font-family: inherit;
 	padding: 0.1em 0.6em;
 	border: 1px solid #ccc;
-	font-size: 13px;
+	font-size: 0.6em;
 	background-color: #f7f7f7;
 	color: #333;
 	box-shadow: 0 1px 0px rgba(0, 0, 0, 0.2), 0 0 0 2px #ffffff inset;
@@ -169,33 +175,69 @@ kbd{
 	white-space: nowrap;
 }
 .taibtn{
-	bottom: 15px;
-	margin: 0 auto;
-	position: absolute;
-	right: 15px;
-	padding: 10px 40px;
-	border-radius: 15px;
-	border: 3px rgba(218, 205, 178, 1) solid;
+	display: inline-block;
+	padding: 0.4em 0.4em;
+	border-radius: 0.5em;
+	border: 0.1em rgba(218, 205, 178, 1) solid;
 	cursor: pointer;
-}
-.taibtn:hover{
-	z-index: 1;
-	color: white;
-	background: rgb(255, 181, 71);
-	border-color: white;
-}
-.taibtn::before{
-	padding: 0 40px;
+	font-size: 1.4em;
+	box-sizing: border-box;
+	color: #555;
+	text-align: center;
 }
 #tutorial-end-button{
-	font-size: 22pt;
+	float: right;
+	padding: 0.4em 1.5em;
+	font-weight: bold;
+	border-color: #000;
+	color: #000;
+}
+.taibtn:hover,
+#tutorial-end-button:hover{
+	position: relative;
+	z-index: 1;
+	color: #fff;
+	background: #ffb547;
+	border-color: #fff;
+}
+.taibtn::before{
+	padding-left: inherit;
+}
+#about-link-btns{
+	float: left;
+	display: flex;
+}
+#about-link-btns .taibtn{
+	margin-right: 0.4em;
+}
+#diag-txt textarea,
+#diag-txt iframe{
+	width: 100%;
+	height: 5em;
+	font-size: inherit;
+	resize: none;
+	word-break: break-all;
+	margin-bottom: 1em;
+	background: #fff;
+	border: 1px solid #a9a9a9;
+}
+.text-warn{
+	color: #d00;
+}
+.link-btn a{
+	color: inherit;
+	text-decoration: none;
+	pointer-events: none;
+}
+.nowrap{
+	white-space: nowrap;
 }
 @keyframes bgscroll{
 	from{
-		background-position: 0 center;
+		background-position: 0 top;
 	}
 	to{
-		background-position: calc(-100vh / 720 * 512) center;
+		background-position: calc(-100vh / 720 * 512) top;
 	}
 }
 #song-select{
@@ -210,9 +252,7 @@ kbd{
 }
 #song-sel-canvas{
 	position: absolute;
-	top: 0;
 	right: 0;
-	bottom: 0;
 	left: 0;
 	margin: auto;
 }
diff --git a/public/src/js/about.js b/public/src/js/about.js
new file mode 100644
index 0000000..a5e52c4
--- /dev/null
+++ b/public/src/js/about.js
@@ -0,0 +1,149 @@
+class About{
+	constructor(touchEnabled){
+		this.issueTemplate = [
+			"###### 下記の問題を説明してください。 スクリーンショットと診断情報を含めてください。",
+			"###### Describe the problem you are having below. Please include a screenshot and the diagnostic information."
+		]
+		
+		this.touchEnabled = touchEnabled
+		loader.changePage("about")
+		cancelTouch = false
+		
+		this.endButton = document.getElementById("tutorial-end-button")
+		this.diagTxt = document.getElementById("diag-txt")
+		this.version = document.getElementById("version-link").href
+		this.tutorialOuter = document.getElementById("tutorial-outer")
+		if(touchEnabled){
+			this.tutorialOuter.classList.add("touch-enabled")
+		}
+		this.linkGithub = document.getElementById("link-github")
+		this.linkEmail = document.getElementById("link-email")
+		
+		pageEvents.add(this.linkGithub, ["click", "touchend"], this.linkButton.bind(this))
+		pageEvents.add(this.linkEmail, ["click", "touchend"], this.linkButton.bind(this))
+		pageEvents.once(this.endButton, ["mousedown", "touchstart"]).then(this.onEnd.bind(this))
+		pageEvents.keyOnce(this, 13, "down").then(this.onEnd.bind(this))
+		
+		this.gamepad = new Gamepad({
+			"confirm": ["start", "b", "ls", "rs"]
+		}, this.onEnd.bind(this))
+		
+		this.addDiag()
+	}
+	onEnd(event){
+		var touched = false
+		if(event && event.type === "touchstart"){
+			event.preventDefault()
+			touched = true
+		}
+		this.clean()
+		assets.sounds["don"].play()
+		localStorage.setItem("tutorial", "true")
+		setTimeout(() => {
+			new SongSelect("about", false, touched)
+		}, 500)
+	}
+	addDiag(){
+		var diag = []
+		
+		diag.push("```")
+		diag.push("Taiko-Web version: " + this.version)
+		diag.push("User agent: " + navigator.userAgent)
+		diag.push("Screen size: " + innerWidth + "x" + innerHeight + ", outer: " + outerWidth + "x" + outerHeight + ", ratio: " + (window.devicePixelRatio || 1).toFixed(2))
+		if(this.touchEnabled){
+			diag.push("Touch enabled: true")
+		}
+		if(!fullScreenSupported){
+			diag.push("Full screen supported: false")
+		}
+		diag.push("Blur performance: " + perf.blur + "ms, all images: " + perf.allImg + "ms")
+		diag.push("Page load: " + (perf.load / 1000).toFixed(1) + "s")
+		if("getGamepads" in navigator){
+			var gamepads = navigator.getGamepads()
+			for(var i = 0; i < gamepads.length; i++){
+				if(gamepads[i]){
+					var gamepadDiag = []
+					gamepadDiag.push(gamepads[i].id)
+					gamepadDiag.push("buttons: " + 	gamepads[i].buttons.length)
+					gamepadDiag.push("axes: " + gamepads[i].axes.length)
+					diag.push("Gamepad #" + (i + 1) + ": " + gamepadDiag.join(", "))
+				}
+			}
+		}
+		var errorObj = {}
+		if(localStorage["lastError"]){
+			try{
+				errorObj = JSON.parse(localStorage["lastError"])
+			}catch(e){}
+		}
+		if(errorObj.timestamp && errorObj.stack){
+			if(errorObj.timestamp + 1000 * 60 * 60 * 24 > (+new Date)){
+				diag.push("Last error: " + errorObj.stack)
+				diag.push("Error date: " + new Date(errorObj.timestamp).toGMTString())
+			}else{
+				localStorage.removeItem("lastError")
+			}
+		}
+		diag.push("```")
+		var diag = diag.join("\n")
+		
+		if(navigator.userAgent.indexOf("Android") >= 0){
+			var iframe = document.createElement("iframe")
+			this.diagTxt.appendChild(iframe)
+			var body = iframe.contentWindow.document.body
+			body.innerText = diag
+			
+			body.setAttribute("style", `
+				font-family: monospace;
+				margin: 2px 0 0 2px;
+				white-space: pre-wrap;
+				word-break: break-all;
+				cursor: text;
+			`)
+			body.setAttribute("onblur", `
+				getSelection().removeAllRanges()
+			`)
+		}else{
+			this.textarea = document.createElement("textarea")
+			this.textarea.readOnly = true
+			this.textarea.value = diag
+			this.diagTxt.appendChild(this.textarea)
+			if(!this.touchEnabled){
+				pageEvents.add(this.textarea, "focus", () => {
+					this.textarea.select()
+				})
+				pageEvents.add(this.textarea, "blur", () => {
+					getSelection().removeAllRanges()
+				})
+			}
+		}
+		
+		var issueBody = this.issueTemplate.join("\n") + "\n\n\n\n" + diag
+		this.getLink(this.linkGithub).href += "?body=" + encodeURIComponent(issueBody)
+		this.getLink(this.linkEmail).href += "?body=" + encodeURIComponent(issueBody.replace(/\n/g, "<br>\r\n"))
+	}
+	getLink(target){
+		return target.getElementsByTagName("a")[0]
+	}
+	linkButton(event){
+		this.getLink(event.currentTarget).click()
+	}
+	clean(){
+		cancelTouch = true
+		this.gamepad.clean()
+		pageEvents.remove(this.linkGithub, ["click", "touchend"])
+		pageEvents.remove(this.linkEmail, ["click", "touchend"])
+		pageEvents.remove(this.endButton, ["mousedown", "touchstart"])
+		if(this.textarea){
+			pageEvents.remove(this.textarea, ["focus", "blur"])
+		}
+		pageEvents.keyRemove(this, 13)
+		delete this.endButton
+		delete this.diagTxt
+		delete this.version
+		delete this.tutorialOuter
+		delete this.linkGithub
+		delete this.linkEmail
+		delete this.textarea
+	}
+}
diff --git a/public/src/js/assets.js b/public/src/js/assets.js
index e289e16..fde1bec 100644
--- a/public/src/js/assets.js
+++ b/public/src/js/assets.js
@@ -123,7 +123,8 @@ var assets = {
 		"loadsong.html",
 		"songselect.html",
 		"titlescreen.html",
-		"tutorial.html"
+		"tutorial.html",
+		"about.html"
 	],
 	
 	"songs": [],
diff --git a/public/src/js/canvastest.js b/public/src/js/canvastest.js
index b952981..dea0bf6 100644
--- a/public/src/js/canvastest.js
+++ b/public/src/js/canvastest.js
@@ -91,6 +91,7 @@ class CanvasTest{
 	drawAllImages(){
 		return new Promise(resolve => {
 			requestAnimationFrame(() => {
+				var startTime = +new Date
 				var ctx = this.ctx
 				ctx.save()
 				ctx.clearRect(0, 0, this.canvas.width, this.canvas.height)
@@ -131,7 +132,7 @@ class CanvasTest{
 				}
 				
 				ctx.restore()
-				resolve()
+				resolve((+new Date) - startTime)
 			})
 		})
 	}
diff --git a/public/src/js/loader.js b/public/src/js/loader.js
index e8bda9d..59954b6 100644
--- a/public/src/js/loader.js
+++ b/public/src/js/loader.js
@@ -5,16 +5,9 @@ class Loader{
 		this.assetsDiv = document.getElementById("assets")
 		this.canvasTest = new CanvasTest()
 		p2 = new P2Connection()
-		this.ajax("src/views/loader.html").then(this.run.bind(this))
+		this.startTime = +new Date
 		
-		pageEvents.add(root, ["touchstart", "touchmove", "touchend"], event => {
-			event.preventDefault()
-		})
-		var versionDiv = document.getElementById("version")
-		var versionLink = document.getElementById("version-link")
-		pageEvents.add(versionDiv, ["click", "touchend"], () => {
-			versionLink.click()
-		})
+		this.ajax("src/views/loader.html").then(this.run.bind(this))
 	}
 	run(page){
 		this.promises = []
@@ -94,6 +87,7 @@ class Loader{
 			})
 			
 			this.promises.push(this.canvasTest.blurPerformance().then(result => {
+				perf.blur = result
 				if(result > 1000 / 50){
 					// Less than 50 fps with blur enabled
 					disableBlur = true
@@ -105,7 +99,9 @@ class Loader{
 			})
 			
 			Promise.all(this.promises).then(() => {
-				this.canvasTest.drawAllImages().then(() => {
+				this.canvasTest.drawAllImages().then(result => {
+					perf.allImg = result
+					perf.load = (+new Date) - this.startTime
 					this.canvasTest.clean()
 					this.clean()
 					this.callback()
diff --git a/public/src/js/main.js b/public/src/js/main.js
index 98f6121..7647985 100644
--- a/public/src/js/main.js
+++ b/public/src/js/main.js
@@ -1,3 +1,16 @@
+addEventListener("error", err => {
+	var stack
+	if("error" in err){
+		stack = err.error.stack
+	}else{
+		stack = err.message + "\n    at " + err.filename + ":" + err.lineno + ":" + err.colno
+	}
+	localStorage["lastError"] = JSON.stringify({
+		timestamp: +new Date,
+		stack: stack
+	})
+})
+
 function toggleFullscreen(){
 	if("requestFullscreen" in root){
 		if(document.fullscreenElement){
@@ -19,6 +32,14 @@ function toggleFullscreen(){
 		}
 	}
 }
+
+function resizeRoot(){
+	if(lastHeight !== innerHeight){
+		lastHeight = innerHeight
+		root.style.height = innerHeight + "px"
+	}
+}
+
 var root = document.documentElement
 var fullScreenSupported = "requestFullscreen" in root || "webkitRequestFullscreen" in root || "mozRequestFullScreen" in root
 
@@ -26,6 +47,27 @@ var pageEvents = new PageEvents()
 var snd = {}
 var p2
 var disableBlur = false
+var cancelTouch = true
+var lastHeight
+var perf = {
+	blur: 0,
+	allImg: 0,
+	load: 0
+}
+
+pageEvents.add(root, ["touchstart", "touchmove", "touchend"], event => {
+	if(event.cancelable && cancelTouch){
+		event.preventDefault()
+	}
+})
+var versionDiv = document.getElementById("version")
+var versionLink = document.getElementById("version-link")
+pageEvents.add(versionDiv, ["click", "touchend"], () => {
+	versionLink.click()
+})
+resizeRoot()
+setInterval(resizeRoot, 100)
+
 var loader = new Loader(() => {
 	new Titlescreen()
 })
diff --git a/public/src/js/scoresheet.js b/public/src/js/scoresheet.js
index 41c57e2..f2b3fdd 100644
--- a/public/src/js/scoresheet.js
+++ b/public/src/js/scoresheet.js
@@ -115,7 +115,7 @@ class Scoresheet{
 		ctx.save()
 		
 		var winW = innerWidth
-		var winH = innerHeight
+		var winH = lastHeight
 		this.pixelRatio = window.devicePixelRatio || 1
 		winW *= this.pixelRatio
 		winH *= this.pixelRatio
diff --git a/public/src/js/songselect.js b/public/src/js/songselect.js
index 53248e9..61a4641 100644
--- a/public/src/js/songselect.js
+++ b/public/src/js/songselect.js
@@ -29,6 +29,12 @@ class SongSelect{
 				border: ["#d6ffff", "#6bae9c"],
 				outline: "#31ae94"
 			},
+			"about": {
+				sort: 7,
+				background: "#91cfff",
+				border: ["#dff0ff", "#6890b2"],
+				outline: "#217abb"
+			},
 			"J-POP": {
 				sort: 0,
 				background: "#219fbb",
@@ -114,7 +120,9 @@ class SongSelect{
 			category: "ランダム"
 		})
 		if(touchEnabled){
-			fromTutorial = false
+			if(fromTutorial === "tutorial"){
+				fromTutorial = false
+			}
 		}else{
 			this.songs.push({
 				title: "あそびかた説明",
@@ -123,6 +131,12 @@ class SongSelect{
 				category: "ランダム"
 			})
 		}
+		this.songs.push({
+			title: "について",
+			skin: this.songSkin.about,
+			action: "about",
+			category: "ランダム"
+		})
 		this.songs.push({
 			title: "もどる",
 			skin: this.songSkin.back,
@@ -155,16 +169,20 @@ class SongSelect{
 		this.selectedDiff = 0
 		assets.sounds["bgm_songsel"].playLoop(0.1, false, 0, 1.442, 3.506)
 		
-		if(touchEnabled || !fromTutorial && "selectedSong" in localStorage){
+		if(!fromTutorial && !("selectedSong" in localStorage)){
+			fromTutorial = touchEnabled ? "about" : "tutorial"
+		}
+		
+		if(fromTutorial){
+			this.selectedSong = this.songs.findIndex(song => song.action === fromTutorial)
+			this.playBgm(true)
+		}else{
 			if("selectedSong" in localStorage){
 				this.selectedSong = Math.min(Math.max(0, localStorage["selectedSong"] |0), this.songs.length)
 			}
 			assets.sounds["song-select"].play()
 			snd.musicGain.fadeOut()
 			this.playBgm(false)
-		}else{
-			this.selectedSong = this.songs.findIndex(song => song.action === "tutorial")
-			this.playBgm(true)
 		}
 		if("selectedDiff" in localStorage){
 			this.selectedDiff = Math.min(Math.max(0, localStorage["selectedDiff"] |0), 4)
@@ -454,6 +472,8 @@ class SongSelect{
 				}, 200)
 			}else if(currentSong.action === "tutorial"){
 				this.toTutorial()
+			}else if(currentSong.action === "about"){
+				this.toAbout()
 			}
 			this.pointer(false)
 		}
@@ -505,6 +525,13 @@ class SongSelect{
 			new Tutorial(true)
 		}, 500)
 	}
+	toAbout(){
+		assets.sounds["don"].play()
+		this.clean()
+		setTimeout(() => {
+			new About(this.touchEnabled)
+		}, 500)
+	}
 	
 	redraw(){
 		if(!this.redrawRunning){
@@ -538,7 +565,7 @@ class SongSelect{
 		
 		var ctx = this.ctx
 		var winW = innerWidth
-		var winH = innerHeight
+		var winH = lastHeight
 		if(winW / 32 > winH / 9){
 			winW = winH / 9 * 32
 		}
diff --git a/public/src/js/tutorial.js b/public/src/js/tutorial.js
index 3f9e1e3..b340d2c 100644
--- a/public/src/js/tutorial.js
+++ b/public/src/js/tutorial.js
@@ -22,7 +22,7 @@ class Tutorial{
 		assets.sounds["don"].play()
 		localStorage.setItem("tutorial", "true")
 		setTimeout(() => {
-			new SongSelect(this.fromSongSel, false, touched)
+			new SongSelect(this.fromSongSel ? "tutorial" : false, false, touched)
 		}, 500)
 	}
 	clean(){
diff --git a/public/src/js/view.js b/public/src/js/view.js
index 99d37ae..a9f5dcf 100644
--- a/public/src/js/view.js
+++ b/public/src/js/view.js
@@ -949,8 +949,10 @@ class View{
 	}
 	clean(){
 		pageEvents.mouseRemove(this)
-		if(this.controller.multiplayer === 2 && this.canvas){
-			this.canvas.canvas.parentNode.removeChild(this.canvas.canvas)
+		if(this.controller.multiplayer === 2){
+			if(this.canvas){
+				this.canvas.canvas.parentNode.removeChild(this.canvas.canvas)
+			}
 		}else{
 			this.cursor.parentNode.removeChild(this.cursor)
 		}
diff --git a/public/src/views/about.html b/public/src/views/about.html
new file mode 100644
index 0000000..5777ea2
--- /dev/null
+++ b/public/src/views/about.html
@@ -0,0 +1,27 @@
+<div id="tutorial-outer">
+	<div id="tutorial">
+		<div id="tutorial-title" class="stroke-sub" alt="について / About">について / About</div>
+		<div id="tutorial-content">
+			このシミュレータは現在開発中です。<br>
+			バグが発生した場合は、報告してください。<br>
+			GitHubかメールでバグを報告してください。<br>
+			<span class="text-warn">以下の診断情報を含めてください！</span><br>
+			<br>
+			This simulator is still in development.<br>
+			Please report any bugs you find.<br>
+			You can report bugs either via GitHub or email.<br>
+			<span class="text-warn">Be sure to include the following diagnostic data!</span>
+			
+		</div>
+		<div id="diag-txt"></div>
+		<div id="about-link-btns">
+			<div id="link-github" class="taibtn stroke-sub link-btn" alt="GitHub">
+				<a href="https://github.com/bui/taiko-web/issues/new" target="_blank">GitHub</a>
+			</div>
+			<div id="link-email" class="taibtn stroke-sub link-btn" alt="taiko@bui.pm">
+				<a href="mailto:taiko@bui.pm">taiko@bui.pm</a>
+			</div>
+		</div>
+		<div id="tutorial-end-button" class="taibtn stroke-sub" alt="OK">OK</div>
+	</div>
+</div>
diff --git a/templates/index.html b/templates/index.html
index d813baf..d4b8f13 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -15,7 +15,6 @@
 	<title>太鼓の達人ウェブ - Taiko no Tatsujin Web</title>
 	<link rel="icon" href="/assets/img/favicon.png" type="image/png">
 	<meta name="viewport" content="width=device-width, user-scalable=no">
-	<meta name="apple-mobile-web-app-capable" content="yes">
 	
 	<link rel="stylesheet" href="/src/css/main.css?{{version.commit_short}}"/>
 	<link rel="stylesheet" href="/src/css/loader.css?{{version.commit_short}}">
@@ -52,6 +51,7 @@
 	<script src="/src/js/canvastest.js?{{version.commit_short}}"></script>
 	<script src="/src/js/canvascache.js?{{version.commit_short}}"></script>
 	<script src="/src/js/parsetja.js?{{version.commit_short}}"></script>
+	<script src="/src/js/about.js?{{version.commit_short}}"></script>
 	
 </head>
 <body>