By default, android phone only notify new message once. The user may miss the incoming messages if he is currently busy. Setting the messaging app to repeatedly alert the unread messages will increase the awareness of the user about the messages. This tutorial will show you how to set up this feature without using any third-party applications.
Please note that this tutorial is for Samsung Android phones only. Phones from other manufactures may also have this feature, but the steps may be different. This tutorial is written based on the Android 4.1.2 Samsung stock rom.
1. Open the messaging app from the app drawer.
2. Wait for the app to open, tap the menu button of your phone, then choose Settings from the list.
3. In the Settings screen, find the Message alert repetition option and tap on it to show the available choices.
4. You can configure the app to remind you of unread message every 2 minutes, 10 minutes or just once (the default option). It is also possible to change this setting later if you find the interval is too long or too short.
5. After choosing the setting, it will be saved and the window will be closed automatically. From now, you will never miss any text messages.