I use my phone calendar and alerts all the time. The "Tripit" app goes beyond that and is even handier/easier for using while on vacation. You can add your flights, hotel confirmations, photos, "plans" for each day of your holiday, etc., etc. I copy lots of tidbits of info that I find here and elsewhere and paste it into the appropriate day or activity I have added. ie: I have a section titled "recommended private taxis" that lists names and phone numbers, comments; another listed "restaurants" that has those on my "to do" list, along with their phone numbers for reservations/pick up.
I use the free version and love it: https://www.tripit.com/uhp/learnMore