Network Type Indicator is an Android app developed by Toni Corvera that allows users to display an icon on their device's status bar indicating the type of cellular connection and whether mobile data is connected or not. This app is particularly useful for devices that do not include this information in the status bar or hide it when roaming.

One of the notable features of this app is that it can work on multi-SIM devices, but only for the primary card. However, some devices, such as Xiaomi/MIUI devices, may display the app's icon instead of the connection type in the status bar, and users will only be able to see the network type information in the app's notification.

It is worth noting that a non-removable notification must be present along the status bar icon due to the way Android works. Additionally, the notification will show in the lock screen in Lollipop and up, and there is no known way to avoid this. Lastly, if the app fails to load on boot or crashes, users can try excluding it from battery optimizations.

Overall, Network Type Indicator is a handy app that provides users with essential information regarding their cellular connection.