Apps to track networking status

This may sound weird but recently I've been trying to track my network in terms of how often I am touch with specific people. Some people I think I should be in touch with 1-2x per year while with others it might be quarterly. Other than just a generic spreadsheet or Evernote, is there anything short of having to use a CRM (i'm not a salesperson and the idea of learning one terrifies me) that anyone can recommend. I realize that this may seem overkill in terms of tracking my network but I really have a terrible memory for details and think its very important to remember what our conversation was about and the date we had a phone call / meeting / lunch last, etc.