I think that most companies that sponsor projects are companies that are using the projects. IIUC https://github.com/nidhaloff/igel is your most popular project. Who is using it?
Don't expect the companies to pay. You can not force them to pay. It's a project with a MIT license. (Perhaps this is obvious for you, but a few days ago someone posted a rant by another developer because some companies were using his MIT-license project and only making a $500 annual money contribution.)
I think one possibility is to write blog post about examples of using the project to solve interesting problems. It's important that they are interesting to get traction here and in other platforms. At the bottom, add a remake explaining that you are the main developer of the project and you'd like sponsors. (I can't guaranty that this will work.)
Also, this helps as an extended documentation of the project and to get more traffic from google and to get more users. All of that can help to increase the user base and hopefully find an sponsor. (I can't guaranty that this will work.)
Thanks for the reply. Of course I'm not "expecting" or forcing companies to pay! It's more of I'm hoping or I hope for support in the future.
Also of course I know everything about open source licenses, so as I said I'm not forcing nothing. Thanks for your hints I will try to apply them and see if it would help ;)
* If you write a blog post, try to add some graphical representation of the problem and the result. If it's not in the program, make it clear that you used other software to graph it (gnuplot? Excel?) But an image is worth a thousand words.
* Can you program solve the problems in Kaggle? Is Kaggle happy if you use their examples/problem and post a solution? It can be another source of ideas, but be careful.
PS: It's nice that you are adding an GUI version. I like to use a GUI version and use the CLI only for weird case or to automate the workflow once it's stabilized.
Don't expect the companies to pay. You can not force them to pay. It's a project with a MIT license. (Perhaps this is obvious for you, but a few days ago someone posted a rant by another developer because some companies were using his MIT-license project and only making a $500 annual money contribution.)
I think one possibility is to write blog post about examples of using the project to solve interesting problems. It's important that they are interesting to get traction here and in other platforms. At the bottom, add a remake explaining that you are the main developer of the project and you'd like sponsors. (I can't guaranty that this will work.)
Also, this helps as an extended documentation of the project and to get more traffic from google and to get more users. All of that can help to increase the user base and hopefully find an sponsor. (I can't guaranty that this will work.)