Here will show you guys on how you can deploy your apps for free without having a domain and hosting, Github has made it easy for you.

Before I proceed I believe you have knowledge of how you can get your files on Github by using git push and commit or you can do it via file uploads.

If not don't skip this step 

Getting your project on Github is very easy, all you have to do is to open an account with GitHub.

Create a Repository

In the navigation on the upper right corner, click the New Repository under the plus icon.

You only need to fill out the details, then and set how you want the repository to be public or private then click Create repository.

On your repository interface, you can now add some files to your repository by using git or file upload

By git

You will see clone at the right side, click on it and copy the https link.

Go to your project and hold shift + right click a menu that will appear click on open in command prompt and type

git clone the link you copied here

If you are using advance IDE just use the IDE terminal and do git clone.

After cloning I you need to initialize the project and commit, after that you push

Note that you must have installed git package on your system before git will work.

Have any questions here drop it 

By file upload

As for the file upload, you can either click Upload files

Note: by default you are in the master branch of your repository.

or can drag and drop your files like so.

As for the commit message, you can type something that describes what you did. If you added some pictures, is your choice, all done

Deploy your website using GitHub Pages

Note that your project must contain home.html or .php or index.html or .php

First, go to Settings and scroll down to GitHub Pages.

Then, click on the master branch. With this, your site is now published at https://yourusername.github.io/respositoryname

  If you want to use https://yourusername.github.io rather than https://yourusername.github.io/respositoryname

you just need to name your repository yourusername.github.io. This is suitable for portfolio websites.

Have any confuse kindly comment to this post