Any good tools for generating world maps and land masses?

Basically wondering if there are any good tools for generating world maps, mostly looking for something that can simulate plate tectonics and generate realistic mountain ranges and rivers and different biomes, just something that can generate a landmass that would be a good start to start populating with cities and points of interest.

Just curious what tools other DMs are using?

Inkarnate has a button to create a random map. Iirc, it’s just landmasses, you have to fill them in/make adjustments to them, but it can be a start. At least on the free version. Not sure what the paid version might do for you. 

I've been thinking of buying Wonderdraft (for world maps) or Dungeondraft (for dungeons and smaller encounters). AFAIK they are paid only (haven't checked if they have a free trial), but it's a single payment, no subscription. But according to adequate Googling, they've received good feedback.

As for just random generation, there's also Azgaar's Fantasy Map Generator, which is a free open-source web based map generator.

Inkarnate is capable of creating the maps you need, but like most things in life has a learning curve. No automatically generated maps are going to give you what you need short of highly niche pieces of software. Wonderdraft is also good if you intend to learn how to use it. One is a minimal £25 per year subscription; the other is a one-time purchase equal to a few years' subscription costs to get hold of everything.

Your genuine best bet if you want something specifically realistic is to pick a piece of software and learn how to use it well. That way you get to ensure that the map is as accurate as you wish it to be. Generative software is universally garbage for anything outside of the narrow purpose it was designed for.

How realistic does it need to be? Do any of your players have degrees in Geology that would mean they will notice and be annoyed if the plate techtonics is wrong? IIRC most fantasy maps are not at all realistic but then they were created by gods and crazy magic not mundane plate techtonics.