diff --git a/package.json b/package.json
index 29ca7b0f..19f2672c 100644
--- a/package.json
+++ b/package.json
@@ -142,6 +142,7 @@
       "NodeList",
       "NotificationEvent",
       "OffscreenCanvas",
+      "PointerEvent",
       "URL",
       "WebSocket",
       "__assets__",
diff --git a/src/inline-script/inline-script.js b/src/inline-script/inline-script.js
index 938431ad..8b737dc3 100644
--- a/src/inline-script/inline-script.js
+++ b/src/inline-script/inline-script.js
@@ -7,6 +7,7 @@ import { INLINE_THEME, DEFAULT_THEME, switchToTheme } from '../routes/_utils/the
 import { basename } from '../routes/_api/utils'
 import { onUserIsLoggedOut } from '../routes/_actions/onUserIsLoggedOut'
 import { storeLite } from '../routes/_store/storeLite'
+import { isIOSPre12Point2, isMac } from '../routes/_utils/userAgent'
 
 window.__themeColors = process.env.THEME_COLORS
 
@@ -51,7 +52,7 @@ if (disableCustomScrollbars) {
 }
 
 // hack to make the scrollbars rounded only on macOS
-if (/mac/i.test(navigator.platform)) {
+if (isMac()) {
   document.documentElement.style.setProperty('--scrollbar-border-radius', '50px')
 }
 
@@ -59,9 +60,7 @@ if (/mac/i.test(navigator.platform)) {
 // for cross-origin authentication: https://github.com/nolanlawson/pinafore/issues/45
 // Here we sniff for iOS <12.2 by checking for the existence of a native IntersectionObserver
 // function, which was added in 12.2.
-if (/iP(?:hone|ad|od)/.test(navigator.userAgent) &&
-  !(typeof IntersectionObserver === 'function' &&
-    IntersectionObserver.toString().includes('[native code]'))) {
+if (isIOSPre12Point2()) {
   document.head.removeChild(document.getElementById('theManifest'))
 }
 
diff --git a/src/routes/_static/media.js b/src/routes/_static/media.js
index 0c7405c0..43d47d41 100644
--- a/src/routes/_static/media.js
+++ b/src/routes/_static/media.js
@@ -1,3 +1,5 @@
+import { isIOSPre13 } from '../_utils/userAgent'
+
 export const DEFAULT_MEDIA_WIDTH = 300
 export const DEFAULT_MEDIA_HEIGHT = 250
 
@@ -51,10 +53,8 @@ const acceptedFileTypes = [
   'video/x-ms-asf'
 ]
 
-const isIOS = process.browser && /iP(?:hone|ad|od)/.test(navigator.userAgent)
-
 // TODO: iOS has a bug where it does not allow audio uploads unless you either *only* accept audio, or
 // you accept everything. Since this is not a great user experience (e.g. it could lead someone trying
 // to upload a PDF, which is not allowed), then we only use the */* for iOS.
 // WebKit bug: https://bugs.webkit.org/show_bug.cgi?id=190982#c2
-export const mediaAccept = isIOS ? '*/*' : acceptedFileTypes.join(',')
+export const mediaAccept = isIOSPre13() ? '*/*' : acceptedFileTypes.join(',')
diff --git a/src/routes/_store/storeLite.js b/src/routes/_store/storeLite.js
index 86f0d0af..3f9cee94 100644
--- a/src/routes/_store/storeLite.js
+++ b/src/routes/_store/storeLite.js
@@ -1,9 +1,9 @@
 // "lite" version of the store used in the inline script.
 
 import { safeParse } from './safeParse'
-import { testHasLocalStorageOnce } from '../_utils/testStorage'
+import { testHasLocalStorage } from '../_utils/testStorage'
 
-const hasLocalStorage = testHasLocalStorageOnce()
+const hasLocalStorage = testHasLocalStorage()
 
 export const storeLite = {
   get () {
diff --git a/src/routes/_utils/runMediumPriorityTask.js b/src/routes/_utils/runMediumPriorityTask.js
index a17c5ffb..597f05ca 100644
--- a/src/routes/_utils/runMediumPriorityTask.js
+++ b/src/routes/_utils/runMediumPriorityTask.js
@@ -1,9 +1,9 @@
 import { scheduleIdleTask } from './scheduleIdleTask'
 import { store } from '../_store/store'
+import { isMobile } from './userAgent'
 
 // Rough guess at whether this is a "mobile" device or not, for the purposes
 // of "device class" estimations
-const IS_MOBILE = process.browser && navigator.userAgent.match(/(?:iPhone|iPod|iPad|Android|KAIOS)/)
 
 // Run a task that doesn't need to be processed immediately, but should
 // probably be delayed if we're on a mobile device. Also run it sooner
@@ -11,7 +11,7 @@ const IS_MOBILE = process.browser && navigator.userAgent.match(/(?:iPhone|iPod|i
 export function runMediumPriorityTask (fn) {
   if (store.get().pageVisibilityHidden) {
     fn()
-  } else if (IS_MOBILE) {
+  } else if (isMobile()) {
     scheduleIdleTask(fn)
   } else {
     requestAnimationFrame(fn)
diff --git a/src/routes/_utils/testStorage.js b/src/routes/_utils/testStorage.js
index 581a7ad7..36bde6d6 100644
--- a/src/routes/_utils/testStorage.js
+++ b/src/routes/_utils/testStorage.js
@@ -5,7 +5,7 @@ import { thunk } from './thunk'
 
 const testKey = '__test__'
 
-export const testHasLocalStorageOnce = () => {
+export const testHasLocalStorage = thunk(() => {
   try {
     localStorage.setItem(testKey, testKey)
     if (!localStorage.length || localStorage.getItem(testKey) !== testKey) {
@@ -16,9 +16,7 @@ export const testHasLocalStorageOnce = () => {
     return false
   }
   return true
-}
-
-export const testHasLocalStorage = thunk(testHasLocalStorageOnce)
+})
 
 export const testHasIndexedDB = thunk(async () => {
   if (typeof indexedDB === 'undefined') {
diff --git a/src/routes/_utils/userAgent.js b/src/routes/_utils/userAgent.js
index 52c6868f..ca00151b 100644
--- a/src/routes/_utils/userAgent.js
+++ b/src/routes/_utils/userAgent.js
@@ -1,3 +1,19 @@
 import { thunk } from './thunk'
 
 export const isKaiOS = thunk(() => process.browser && /KAIOS/.test(navigator.userAgent))
+
+export const isIOS = thunk(() => process.browser && /iP(?:hone|ad|od)/.test(navigator.userAgent))
+
+export const isMac = thunk(() => process.browser && /mac/i.test(navigator.platform))
+
+// IntersectionObserver introduced in iOS 12.2 https://caniuse.com/#feat=intersectionobserver
+export const isIOSPre12Point2 = thunk(() => process.browser && isIOS() &&
+  !(typeof IntersectionObserver === 'function' &&
+    IntersectionObserver.toString().includes('[native code]')))
+
+// PointerEvent introduced in iOS 13 https://caniuse.com/#feat=pointer
+export const isIOSPre13 = thunk(() => process.browser && isIOS() &&
+  !(typeof PointerEvent === 'function' &&
+    PointerEvent.toString().includes('[native code]')))
+
+export const isMobile = thunk(() => process.browser && navigator.userAgent.match(/(?:iPhone|iPod|iPad|Android|KAIOS)/))