What tools for tracking off market leads?

[Corbett Brasington]

What tools are you using for tracking off market leads?  You drive for dollars....get a 10 homes you want to whole sale....you need a place to track them, find out how to contract them, contact them, then close them on you selling their home.  

Google sheets and excel is simple answer but is there anything better?  I would like something that helps me track conversion rate and other ratios so I can improve my business as I go.