Following a modelisation of the price variation by Fractional Brownian Motion, this indicator increases the width the Bollinger Bands in order to avoid (or minimize) false signals (of entry or exit). For a more complete explanation, please see my blog:
Here is what this indicator looks like for a speed of the FRASMA ( set to 30. The red indicator is the Fractal Bands, and the blue is the Bollinger Bands (with a speed set to 30 as well), below is the Fractal Graph dimension (