JTrack EMA+¶

JTrack EMA is available for Android and iOS:

In the Google Play Store
In Apple’s App Store

To install this app, first go to the Google Play Store on your Android phone.

What JTrack EMA+ Can Do¶

Broad question types: binary, date/time, duration, sliders, single/multiple choice, and more.
Platform-independent UX with paging for long surveys, language support, and survey categories to keep forms organized. It also provides a similar user experience on both Android and iOS devices.
Dynamic survey updates from server so questionnaires and media/images can be revised mid-study without reinstalling the app.
Save & Resume with answered items highlighted so surveys can be resumed where they were left.
Conditional logic to show/hide questions based on earlier answers, improving relevance and reducing cognitive load.
HTML text formatting support so question text and subtext can include simple inline formatting.
Integrated calendar events for time-sensitive prompts so reminders can be added to the phone calendar.
Local Administration Menu for on-device management tasks (study setup, diagnostics, etc.).

Prerequisites¶

Your study coordinator has provided a QR code to join the study.
A stable internet connection for initial setup and survey/media updates.

Android - Install & Join the Study¶

1) Install the App¶

Open the Google Play Store on your Android device.
Search for JTrack EMA+ and install it.

2) Join the Study¶

Open JTrack EMA+ and tap Join study.
When prompted, allow Camera access so the app can scan your study QR code.
Use your device camera to scan the QR code provided by your study team.

Important

For more about the study QR code, including how it is generated, see your project’s QR code documentation.

3) Complete Required App Settings (only if required)¶

After a successful login, the app will prompt you to adjust system settings to ensure reliable background operation.

Follow the in-app prompt to open App settings.

Using JTrack EMA+¶

Starting a Survey¶

Surveys appear according to your study schedule or through prompts configured by the study team.
If no active questions are shown, pull the screen down to refresh.
Long surveys can open in a list view, while short surveys may use paging. Progress is saved automatically.

Calendar Reminders¶

Some studies can create calendar events on your phone so you receive calendar notifications when a survey is scheduled.
When the app shows the Add Event dialog, choose your preferred phone calendar from the list and tap Add Event.
If you do not want to add the reminder immediately, tap Not Now. If you never want the event added for that prompt, tap I Don’t want.
Once the event is added, your phone calendar can notify you at the scheduled survey time.

Save & Resume¶

You can leave the survey at any time. When you return, your saved answers are preserved and answered items remain highlighted for easier navigation.

Leaving a Survey with Unanswered Questions¶

When you reach the last page and tap Submit survey, JTrack EMA+ checks whether any questions are still unanswered.
If questions are missing, the app shows a confirmation dialog with the number of unanswered items.
Choose Return to questionnaire if you want to go back and answer more questions before submitting.
Choose Submit, answer unanswered questions later if you want to leave the remaining questions for later. In that case, the unanswered questions stay open and can be shown again later.
Choose Submit, I have answered all questions if you want the remaining unanswered questions to be treated as questions you do not want to answer. In that case, those questions are not shown again.
This gives the user two different ways to leave the survey, depending on whether unanswered questions should remain pending or be treated as intentionally skipped.

Media & Image Sync¶

If a survey references images or media, the latest assets are pulled from the server automatically.

HTML Formatting in Questions¶

JTrack EMA+ supports a small set of HTML tags in question text and subtext. This can be used to format questionnaire content without changing the app itself. Supported tags are:

 and  for bold text
 and  for italic text
 for underlined text
  for a line break

Variants such as   and   are also accepted and rendered as line breaks.

Conditional Logic¶

Some questions appear only if earlier responses meet certain conditions. This keeps surveys shorter and more relevant.

Troubleshooting¶

I can’t scan the QR code

Ensure you granted Camera permission, increase screen brightness on the QR code source if needed, and hold the device steady about 15 to 25 cm from the code.
Survey reminders are not arriving

On Android, verify Battery optimization is Unrestricted, make sure Remove permission and free up space is disabled, and check whether Do Not Disturb or Focus modes are blocking notifications.
A permission was denied by mistake

Go to System Settings -> Apps -> JTrack EMA+ and enable the required permission again.