Signal Strength supports many network types, including 3G (UMTS), 4G (HSPA+, no WiMax), and 4G LTE.
When starting the app, the main screen describes the app's purpose and contains two buttons, 'Disable/Enable' and 'Hide App'.
I'd love to have others use the app and let me know of any problems.
I have tested this app on the Nexus 5, Nexus 7, and HTC One S.
-- KNOWN PROBLEMS --
- LTE sometimes doesn't give the same reading as other apps and 'About Phone -> Status'
- The notification sometimes stops updating
- Two notifications may appear if you reopen the app (hard for me to reproduce)
-- FUTURE UPDATES --
- The dBm text in the notification bar will show the actual dBm strength
- LTE will be precise