Today, there is an app, website, or software platform for just about anything (including finding someone to walk your dog).
But when it comes to worldbuilding, there is 1 website I can't live without:
World Anvil
And here's why:
It's built to organize your world into a wiki for ease of use. No more stress over how to link information together; each topic can have its own page and link together to create a cohesive project.
There are templates to get you started. The templates are a game changer. They make it so easy to create a well-developed article that includes all kinds of information that can lead to more articles and ideas!
The community is extremely supportive and willing to give feedback. This is especially clear when participating in the monthly or yearly challenges. Many people make it a goal to read as many other articles as possible, and there is always someone willing to lend a hand to brainstorm!
There are tools for building RPGs and creating interactive elements. While not everyone is interested in building an RPG, being able to create interactive parts to articles is a really cool way to let readers engage further with your world.
It's possible to write your novel on the site alongside your world. One of the more interesting features I'd like to explore, the manuscripts feature lets you reference any of your worldbuilding while writing your story and then publish or download it when you're done!
If you want a place to get your worldbuilding organized, meet new writers more than happy to discuss world mechanics, or create a beautiful and interactive interface for readers to engage with your story, I can't recommend using this website enough.