Battery optimization settings on an Android phone can cause long delays between when the notification was sent and when it is actually received. You can modify the battery optimization settings per app in an android phone. To change the battery optimization settings for the Psychexp web app, go to SETTINGS --> APPS --> PSYCHEXP --> BATTERY and change the setting to UNRESTRICTED. This setting should allow the notification to be received and displayed immediately after it is sent. Please note that depending on the android version and the brand of your phone the above settings may differ. If your phone settings seem to differ, please do an Internet search for "Android app battery optimization" (+ add your phone brand) and check the battery optimization settings for your brand of phone.
If you have deleted the Psychexp app you can install it again by using the registration link you originally used to register for the project.
If the project you are participating in required an email address to be entered into the Psychexp app when you originally registered, when you re-install the Psychexp web app and enter the 4 digit code, provided you use the same email address to register as you previously used, then all of your past signal data from the project will be restored. If you are participating in several projects and you used the same email address when you registered, restoring one project will automatically restore all other projects.
If a project you are participating in did not require an email address, you can re-register for the projects by using the original registration link that you received, however past data will not be restored, and basically you will be registered again for the project as a new user.