You can do this with the stock iOS Maps app and the locations can be saved.
1. Drop a pin.
2. Tap the square icon with the arrow in the upper right corner.
3. Select "Add to favorites."
4. Repeat for multiple pins and add custom names if you prefer.
5. To load dropped pin locations, tap the search bar in the Maps app, select "Favorites," and choose a pin/location. You can route directions back to it once it's loaded.