I have been using Dungeondraft and Dungeon Alchemist. Dungeondraft I like more for detailed and customized maps. I like how fast Dungeon Alchemist is, but the lack of certain drawing tools makes it a bit frustrating
Depending on the the type of map I’ll use Adobe Fresco or Illustrator on an iPad. Although I’ll sometimes grab a high resolution scan of a real atlas and draw on it with Procreate.