BIG SMS can show an incoming SMS in a full-screen window over the lock screen when it is the default messaging app and Android allows its normal notifications and full-screen intent access. Turn on Full-screen display over the Lock screen in Preferences → Messages, then check both Android permissions that control the message notification.
Set the message role first, enable the BIG SMS option, and then grant normal notification and full-screen access where Android provides them.
Make BIG SMS the default messaging app
Open BIG SMS and accept its default-app prompt if it appears. Otherwise use System settings → Apps → ⋮ → Default apps → Messaging app, then select BIG SMS for Seniors. The default role is the starting point for normal SMS receive and reply behavior.
Enable the BIG SMS display option
In BIG SMS, open Preferences → Messages. Turn on System Message notification, open Sound and visual configuration, and enable Full-screen display over the Lock screen when the option is present.
Allow Android notifications
On Android 13 and later, allow notifications for BIG SMS. The documented settings path is System settings → Notifications → See all → BIG SMS for Seniors; enable notifications there if they are off. Android 13 and later can keep notifications off until the runtime permission is granted.
Allow full-screen intents on Android 14 and later
Open Settings → Special App Access → Manage full screen intents. If BIG SMS for Seniors is listed, allow its full-screen access. When that access is off, Android may show a heads-up notification instead of opening the full-screen message, so check this permission before changing other SMS settings.
Read and reply from one incoming SMS
- Lock the phone and send an ordinary test SMS from a known number.
- Check whether BIG SMS opens over the lock screen. If it does not, check the BIG SMS notification setting, Android notifications for BIG SMS, and Manage full screen intents.
- Read the incoming message, tap Reply, type a short answer, and tap Send.
Make incoming texts easier to notice
Set BIG SMS as the default messaging app, enable its full-screen message option, and check the Android permissions on the phone you will use.
