I was recently working on a route, and I'll share with you the notes I took for the area:
gfk - restaurants
North Fork Research - grocery stores
customer impact - dinner, $170 reimbursement
BARE - $90 meal reimbursement
KSS Int'l - oil change
Alta360 - grocery store
Reality Check - grocery store
I wrote these notes on a regular lined sheet of notebook paper, and placed it in a manila file titled with the city's name. So when I'm ready to work up the route, I know which companies to contact. I'm a low tech person -- and I know if I put this info on my phone, I'll hit the wrong button or push the wrong something-er-other and it will disappear forever.
I hope this helps.