Android spectrum with digital level of a particular frequency

Hi, I am using rtl-sdr direct connectivity with my android mobile handset. I am able to connect my handset to sdr but i am not able to find an app which shows signal level in dBm at any selected frequency. I need an app which can show the signal level for a chosen frequency as shown by most of signal analyzer. I
I believe your assistance would be invaluable.

Thank you for considering my request. I look forward to your response.

Admin Edit: removed unnecessary details.