Short answer
Install the "截图加日历" (Screenshot to Calendar) shortcut from inside SnapCal, then go to Settings > Accessibility > Touch > Back Tap on your iPhone and point Double Tap at that shortcut. From then on, double-tapping the back of the phone in any app takes a screenshot, reads the time in it in the background, writes the event to your calendar and sends a notification, without opening SnapCal. One screenshot makes one event.
Setup takes three steps, once
- Turn on permissions. In SnapCal open the one-tap setup screen (titled "一键截图，秒进日历" in the Chinese interface) and switch on calendar access and notifications first. Doing it ahead of time means no permission pop-up interrupts a background save later.
- Install the shortcut. Tap the install button on that screen. It opens the Shortcuts add screen with a ready-made shortcut named "截图加日历": it takes a screenshot and hands it to SnapCal to add the event. Tap Add. If you prefer to build it yourself, the same screen lists the manual steps.
- Bind a trigger. Open Settings > Accessibility > Touch, scroll to Back Tap, choose Double Tap (or Triple Tap), and under Shortcuts pick "截图加日历". Per Apple, Back Tap needs an iPhone 8 or later running iOS 14 or later.
Then go to any screen and double-tap the back once. For the first try, use a page with a clear date and time so you can judge the result.
Two other triggers if you do not like Back Tap
- Action button: on models that have one (the app says iPhone 15 Pro and later), go to Settings > Action Button, swipe to Shortcut and choose "截图加日历".
- Floating button: turn on AssistiveTouch under Settings > Accessibility > Touch, then point a custom action such as double-tap or long-press at Shortcuts > "截图加日历".
All three run the same shortcut, so pick whichever is easiest for you. The app lists Back Tap first because it takes no screen space and no hardware button.
What happens after the trigger
The system captures the current screen, the screenshot is read in the background, and once the title, date, start time and place are found the event is written to the calendar and you get a notification. The rules match picking an image inside the app: when title, date and start time are all present, confidence is high enough and the screenshot is not a chat, the event is written directly with a 10-second undo. Otherwise you open the app and check it on the confirmation screen. Chat screenshots (WeChat, iMessage, DingTalk and similar) always go to confirmation first; the reason is in the complete guide. Tencent Meeting, Feishu Meeting and Zoom links and meeting IDs in the screenshot are copied into the event notes.
What it cannot do, and what to watch for
- One screenshot makes one event. A whole timetable, or a page with several events on it, is not split into several events.
- The time has to be on screen. If the date or time is incomplete, the app sends you to the confirmation screen instead of guessing one.
- Back Tap can misfire. A knock on a desk or a phone in a pocket can take a stray screenshot. It stays in your photo library, nothing is added to the calendar if it holds no event, and the free quota (10 a month) is only used when a save succeeds.
- iPhone only. There is no Android version.
- No calendar access, no event. If calendar permission was denied, re-enable it for SnapCal in the iPhone Settings app.
FAQ
Do I never have to open SnapCal again?
Not for the everyday case. Chat screenshots, low-confidence reads and unclear dates still ask you to open the app and check them on the confirmation screen.
I already installed the old "截图加日历" shortcut. Do I need to redo it?
The old one keeps working. To switch to the new one, tap the install button in the app again and then point Back Tap at the newly installed shortcut.
What if my iPhone has no Back Tap?
Back Tap needs an iPhone 8 or later and iOS 14 or later. On older models use the floating button, or screenshot and share it to SnapCal from the share sheet.
Sources and verification
The Back Tap path and device requirement come from Apple's own pages, checked on 2026-10-30: Run shortcuts by tapping the back of your iPhone and Use Back Tap on your iPhone. Menu names can differ slightly between iOS versions, so go by what your phone shows. The rest was checked against the SnapCal 1.11.0 setup screen.
