How do you track your leads?

[Marine Palamutyan]

Hi all! 

How do you track your leads?  I started with only a few potential properties, so the rental calculator was a good tracker for me for a while, but now there are too many and I would like to make notes on progress and track follow ups I need to do.  I was going to create a rough excel spreadsheet to jot down some notes, but wanted to see if anyone has a good template or a program they would recommend.

Thank you in advance for your input! :)