Hands-Face Distance matters as the social distance

No Face-Touch App

An Open Project to Avoid Touching Your Face

by #SIRSLab

This is a project by University of Siena in collaboration with the Istituto Italiano di Tecnologia

Main idea creators and developers: Domenico Prattichizzo, Tommaso Lisini, Gianluca Paolocci, Nicole D'Aurizio, Sara Marullo, Annino De Petra

Video with english captions automatically generated

Latest News

  • No Face-Touch App has been released on Google Play Store. Click HERE to download it!

  • The WearOS APK is already available in the How To Download section. You can install it following the given instruction.

  • No Face-Touch App will be soon available on App Store by Apple.

What is it?

A quick and easy solution to avoid getting the hands close to the face, to prevent Covid-19 infection, especially useful in public places. If you have a smartwatch with the WearOS operative system, all you have to do is download the NO FACE-TOUCH app, attach a magnet to a necklace (or a different accessory worn close to the face) and follow the instructions. The whole setup takes 5 minutes at maximum.

The app is open-source, as explained in the next sections, and everyone can contribute to help people dealing with the Covid-19 emergency. Hopefully, the use of this app might be extended to different devices in the next weeks.

The Vision

We want to help people to come back to their daily habits while reducing the risk of getting and spreading the virus. To do so, we developed an app that does not require any external device except for the smartwatch (also the smartphone may be used after an adaptation) and a hand-made necklace with a magnetic pendant. The app once launched runs on the background and alerts the user every time she/he moves the hand too close to the face. This simple solution may considerably help people feeling safer when going out for work/shopping during quarantine, and will be useful after the lock-down period to avoid virus comebacks.


As shown in "Kwok YL, Gralton J, McLaws ML. Face touching: A frequent habit that has implications for hand hygiene. American journal of infection control. 2015 Feb 1;43(2):112-4," we touch our faces 23 times per hour in average and this is a common vector for the transmission of respiratory infections, as coronavirus. This is the reason why washing our hands is paramount in this COVID-19 pandemic.

In "Dimond S, Harries R. Face touching in monkeys, apes and man: Evolutionary origins and cerebral asymmetry. Neuropsychologia. 1984 Jan 1;22(2):227-33," authors show that among primates, including humans, one of the two hands was more prone to touch the face: the left hand.

A nice article summarinzing these ideas and talking about why we cannot stop touching our faces has been published on WIRED on March 2010.

Moreover consider that it is very important to not touch our face and to wash our hands because Respiratory Syndrome (MERS) coronavirus or endemic human coronaviruses (HCoV) can persist on inanimate surfaces like metal, glass or plastic for up to 9 days as proved by scientists in "Kampf G, Todt D, Pfaender S, Steinmann E. Persistence of coronaviruses on inanimate surfaces and its inactivation with biocidal agents. Journal of Hospital Infection. 2020 Feb 6."

Our Idea

To help us stopping to touch our faces we developed a simple and free app that let your smartwatch vibrate and ring as soon as you get closer to your face. The face is detected by using a small cheap magnet at your necklace.

The smartwatch is worn on the arm whose hand more frequently touches your face. We are using it on the left arm but you can choose the one you like. Of course we cannot alert if the hand without the smartwatch touches your face but we hope that preventing one hand only to touch our face can help us building safe habits for both hands. In any case for sure we reduce the risk by a factor 2.

How it works

NO FACE-TOUCH app is meant to detect when the hand gets too close to the face, and sends alerts to inform the user not to touch the face. To estimate the hand position with respect to the face, the app leverages on the magnetometer embedded in the smartwatch and a magnet mounted on a wearable accessory like a necklace, an earring or glasses (see the “Do It Yourself” section to have some suggestion on how to place them). Whenever the magnetometer detects high values of the magnetic field, the user receives a vibration and an audio notification about the proximity of the hand to the face.

Using this app is simple and requires only few steps:

Download the app on your smartwatch (see the How to Download/Install section) and get some magnets.

Choose your favourite accessory to wear and attach the magnets on it.

To have a more precise ‘protection’, consider using 2 or 3 magnets at different locations.

How it works: accelerometer version

Apple watches version 3 and 4 are not equipped with a magnetometer, thus they cannot exploit the magnetic field created by the hand-made accessory to detect hand proximity. To extend the use of the NO FACE-TOUCH app to a wider spectrum of devices, we developed a smartOS version that only uses accelerometer measurements to infer upwards hand movements. This functionality is available for every smartOS device, and will be extended to wearOS too.

In detail, the app looks for the angle recorded at the wrist to estimate its orientation, and checks if the hand is rotating upwards. If those conditions are met, the app inspects the acceleration along the vertical axis to know if the hand is moving upwards.

Open Source and GitHub

NO TOUCH FACE app is thought to be a continuously growing project. The software is open source and everyone can contribute to improve its efficacy. Although the use for the COVID-19 emergency is the most urgent now, we think that this solution may be useful in daily life to reduce spreading of diseases transmitted by contact, and more generally to avoid touch the face with hands.

The GitHub Repository

To contribute access the GitHub Repository https://github.com/sirslab/COVID-19-DoNTYF-wear

App User Guide


Launch NO FACE-TOUCH app.


Tap on the screen to start.


Read the privacy policy, and if you agree with terms press accept.


Select the hand on which you wear the smartwatch.


Click START CALIBRATION to calibrate the magnetic sensor.


Wait until the blue band at the top becomes green, i.e. until the calibration phase is done.


This is the actual application main screen: here is a User Interface to set automatic or manual calibration, a visual indicator that displays the detected magnetic field amplitude and alerts the user by changing colors.

Considering that iron objects and electrical systems in the surroundings greatly affect the magnetic field measured by the watch, the app often runs an automatic calibration process to estimate the average magnetic field, and senses variations with respect to the average value. This approach makes sure that the app adapts to different contexts and keeps its functionality.

How to download

The app can be downloaded from the official app store (Google Play) or can be installed manually after downloading the APK.

While the first method is straightforward, the second will be detailed in the following section.

Requirements: smartwatch with WearOS, APK (download here) and Minimal ADB and Fastboot software (download here).

  1. First, enable the Developer Options on the Smartwatch:
    Settings -> System -> About -> Tap 7 times on Build Number.
    You should receive a notification saying that Developer Options have been enabled.
    Settings -> Developer Options -> enable Debug ABD and Debug over Wi-fi. Write down the IP address of your device that will be required later (something like

  2. Install the Minimal ADB and Fastboot software (available for Windows and Mac) to upload the APK onto the smartphone.

  3. After installing the software, open the file explorer and go to C:\Program Files (x86)\Minimal ADB and Fastboot folder. Create a new folder called apps, then move the APK inside the apps folder.

  4. Launch the ADB software and connect using the smartwatch IP address. Write the following command, replacing the [IP ADDRESS] with the device IP.
    adb connect [IP ADDRESS] example: adb connect
    Then press ENTER and wait for the confirmation message.

  5. Load the APK on the smartwatch with the following command, replacing [APK file name] with the name of the APK previously downloaded.
    adb push apps/[APK file name] /sdcard/
    adb push apps/DTYF.apk/sdcard/
    ress ENTER and wait for a confirmation message. It might take few minutes.

  6. Install the App with the command
    adb -e install apps/[APK file name] example: adb -e install apps/DTYF.apk
    Press ENTER and wait for the confirm message. Now the app is installed on your smartwatch.

  7. Last Step: close the connection with the device with the following command, then press ENTER
    adb disconnect

Eligible Devices

This app can be installed in every smartwatch featuring the WearOS operative system.

Here is a list of most common WearOS smartwatches:

  • Huawei Watch 2

  • Fossil Sport/Gen 5

  • LG Watch Style

  • LG Watch Urbane2

  • TicWatch E2/Pro/S2/C2

  • Misfit Vapor 2

  • Kate Spade Scallop Smartwatch 2

Please note that this is an open project and more devices will be added to this list as soon as we develop the app for other operative systems. Stay tuned!

The watchOS version is going to be released soon. For older devices (iWatch prior to 5) that do not integrate a magnetometer, we developed an alternative version leveraging on accelerometer measurements only. This functionality is available also for new devices, that will offer the opportunity to choose in-app between the two alternatives.

How to help :)

Either if you are an app developer or you know someone skilled/talented, your contribution can help us extend the app usage to the widest spectrum of wearable devices, and thus people.

The source code is available at https://github.com/sirslab/COVID-19-DoNTYF-wear and everyone can contribute by improving its functionality and usability.

In particular, the aid of developers expert in smartwatch operating systems different from WearOS (like the ones running on Apple, Samsung and Huawei watches) would be extremely valuable.

Useful links

Here some links that may help you in developing, enhancing, and sharing the project: