How long will it take to develop a Java application?

Question

Java

I would like to write an application that will teach sorting algorithms.

1. Display the permutation of elements step by step using the selected algorithm.
   
2. Visually show the permutation animation using shapes (different in size).
   
3. To give the user the opportunity to compose this algorithm from blocks.
   
4. Save the user's progress on the server and throw out articles educational articles in case of correct passage.
   

I planned to run it on Windows, I just don’t know how much more difficult it will be to make it cross-platform. If not much, then you can tighten up.
I was going to write the application in intellij idea for the graphic component, I was advised to use JavaFX, and I added the fourth item there to learn how to use SQL.
The application must have sorting algorithms such as: bubble, Shell, Hoare, choice.
Maybe I'll include "inserts" there, but it simply doesn't seem useful to me in any way. For starters, just this.
Next, I plan to add the implementation of the stack, queue and list, operations with matrices and linear operators, as well as add differentiation and integration with graphs and try to explain everything clearly and clearly.
I would like to know people who are knowledgeable, in how many days and hours these days it is approximately possible to make such an application. And I will be glad for advice on which technologies are better to use, which ones would fit better than what I chose, what to pay attention to. I'm doing this as my first serious project. Thanks in advance.

Answer 1

I don’t know how much more difficult it will be to make it cross-platform. If not much, then you can tighten up.

Java is cross-platform in its essence, you have to strain to make an unportable application on it.
Some can do it in a day, some can't do it in a year. Which one do you belong to?

Answer 2

Disagree, hardly a day. The week is gone.
And if the UI from scratch do it in general a couple.