CellMapper

As the name of the application suggests, CellMapper is an application that provides users with an accurate map of the cellular network around your location. Regular users don’t need this kind of information, but there is a lot of useful data available.
For example, CellMapper displays low-level cellular network information data along with frequency band calculations, which is available for some providers, the app can read the cellular frequencies of some devices that are running at least Android 7.x, and it shows a map of both coverage and individual tower sector coverage and bands.
The current networks supported includes GSM, UMTS, CDMA, LTE, and LTE-A.