One of my favorite apps is PeakFinder, it shows local topography in an AR style UI. It also shows where and when the sun will set given the mountains around you! Well worth the few bucks.
Agreed! It's one of these apps (Similar to Flightradar) that just feel like a great use of technology and add a little bit of joy.
Definitely one of my favorites too! In my experience though it's best used at the location you're expecting the sunset, tricky to see when a specific point elsewhere will have their sunset (it may have changed though, I should check this)