[Android] Network Cell Info & Wifi Free (U.P. $2.99) @ Google Play Store

Network Cell Info is an extensive mobile network and Wi-Fi monitoring app with measurement and diagnostic tools (5G, LTE+, LTE, CDMA, WCDMA, GSM). Network Cell Info can help troubleshoot your reception and connectivity problems while keeping you in the know about your local cell carrier radio frequency landscape.

Appears to be 3 versions of this app, the lite version (free), the standard version (this app, normally $3.19) and pro which is a $3.99 subscription. Manual

via snark at OzBargain