I had some great feedback with Hackaday members. There was recommendation for GNU Radio. So, I wanted to do a further detailed analysis on what are the options, and pros and cons of using the software options. 

GNU Radio Companion (GRC)

• Pros:
  • Extremely powerful and versatile, designed for both simple and intricate signal processing tasks.
  • Modular graphical interface for drag-and-drop processing blocks.
  • Rich library of pre-built modules and functions.
  • Highly customizable and extendable with new modules.
  • Strong community support and a plethora of online tutorials and resources.
• Cons:
  • Can be resource-intensive, which might challenge the Raspberry Pi's capabilities for complex tasks.
  • Has a steeper learning curve, especially for those unfamiliar with signal processing

While GNU seems to be the top contender, I am also liking GQRX distribution. GQRX is very simple, and it is also opensource. And in my experiments, GQRX consumes less power. So, when the 10,000 MaH battery on the SDRDock gets low, SDR++ glitches due to lack of power, while GQRX keeps running when battery gets low.