For the car:
Waze. It's great for real time traffic with crowdsourcing, but the map graphics seem a bit stale. Also, it's now available on Apple Carplay, but I find it lags a bit when turning which is annoying in cities where you have to make a few quick turns. I find myself using my car's gps or google maps more than Waze.
Shazam. When you hear a song on the radio and they don't tell you what the hell it is!
Few others (with descriptions) that I haven't seen mentioned:
Dark Sky. Very cool weather app that tells you about precipitation in your specific location in real time. It will tell you when it's going to start / stop raining, and it's very accurate.
Dashlane. It's getting too expensive, but it's a must in today's password society.
Starbucks. I like coffee.
Ring. It's been fun this Halloween when kids "ghost" our house (ring/run and leave candy for my kids). Some of the kids know what a Ring doorbell is so they try to hide, which is even funnier.
Mouthy. Totally random. It reads back anything you type in Siri's voice. People believe that when I ask Siri who the biggest a!@hole is, Siri responds that "[John] is currently considered the biggest a!@hole in the world."
Slopes. Kind of fun ski tracker.
Tripit. Great way to keep track of your travel info. Just forward all of your confirmation emails (air, hotel, car, restaurant, etc) to Tripit and it organizes them all as an itinerary.
WhiteNoise. There are a bunch of these. Helps me sleep on the road (and home).