Fruity dB Meter: is a large-display peak meter in a dB (decibel) format. Any signal above -6 dB is displayed in orange. See the Levels & Mixing section for an explanation of why levels over 0 dB may not be a problem. Hold the mouse cursor over the display to see the decibel level. Right-click it to reset the peak holds.
Related plugins: Wavecandy has a range of fully customizable metering options covering most common metering types.
Fruity dB Meter can be set at various points in the Fx chain, to check levels before and after different effects (e.g. compressors).
NOTE: there is also an General Settings option Alternate meter scale that will change the scaling of all FL Studio peak meters.