Created a PHP/MySQL application called "Todo List" that allows users to create and manage tasks and goals. It includes features such as setting task deadlines, editing, canceling, deleting tasks, and maintaining personal user accounts. The application is currently in active development, with future plans to add additional functionalities.

Now, where can this application be showcased and promoted? Which hosting platforms or websites are suitable for promoting such an app?

Congratulations on the release of your project. Congratulations that you find yourself in a situation where nobody really needs your product. Congratulations that you are starting to ask yourself how to proceed!

Practice has shown that there are three ways to promote your product while keeping in mind the limited availability of funds:

1) Paying for promotion is undoubtedly the most effective and reliable option. However, this requires having more money than your competitors.

2) Providing unique functionality can also help your solution gain traction. This means offering something that people urgently need but is not available from your competitors. In situations where people are desperately searching for such a solution, they will be grateful for finding it.

3) Sometimes luck plays a role in the success of your project. For example, your project may randomly appear at the top of search results or get noticed and used by a major player. Although this scenario is like winning a lottery, it does happen occasionally.

It is important to note that points 1 and 3 heavily rely on financial resources and luck. Therefore, if you lack substantial funding, it is best to focus on point number 2. Since big players usually dominate the market by fulfilling basic needs with significant financial backing, smaller niches present the most promising opportunities. These niches may not have intense competition but still offer potential for monetary gains in case of success.

Please share your code and/or demonstrate its functionality.
There is a high probability that your code, project, and its purpose are not valuable. This is because if you search online, you can find numerous alternatives that are free and considerably superior.

Furthermore, based on my personal experience, developing your own product or project in 2019 is not advisable.
I have a classifieds website built on a custom object framework, which required an immense amount of coding and over 100,500 man-hours. However, it burdens me greatly as it fails to generate any significant results. I continue to invest money into advertising and occasionally make improvements, but the outcome remains zero. Perhaps it would have been wiser to spend that time on personal enjoyment and leisure activities. Seriously.

It is highly unlikely that your projects will yield financial returns at present. You simply cannot compete with established companies that have dedicated teams of developers and sufficient investments. Any individuals who have achieved success with their projects or websites are either long-standing players within their respective industries or simply fortunate.

1) SEO - optimizing the website for search engines, so that anyone searching for a similar solution can find the site.
2) Advertising on platforms like Google, Yahoo, AdWords, and LinkedIn (Facebook, VK - targeting specific groups is necessary for effective reach).
Reaching out to bloggers, editors, and offering them the product, as well as advertising on forums may not yield significant results, but it's worth exploring all options if the product isn't gaining traction.
On Rsdn, one can engage with people in the shareware section for feedback and suggestions.
Promoting a product is more challenging than writing it. It requires continuous effort and commitment, potentially taking more than a year. There are numerous strategies available; the key is to select the most suitable one.
It's crucial to accurately assess competitors and understand the product's value proposition.
Efforts and advertising budget cannot be easily offset; it requires careful planning and execution.

I would recommend showcasing and promoting your "Todo List" application in several ways to maximize its visibility and reach.

You should consider hosting the application on a reliable and secure hosting platform. Look for a hosting service that provides support for PHP and MySQL and offers features such as easy deployment, scalability, and good server performance. Platforms such as Amazon Web Services (AWS), Google Cloud Platform, or Microsoft Azure are suitable choices for hosting web applications and can provide the necessary infrastructure for your "Todo List" app.

Next, consider creating a dedicated website or landing page for your application. This website should effectively communicate the features, benefits, and unique selling points of the "Todo List" application. It should also include compelling visuals, user testimonials, and a clear call-to-action for visitors to try out or purchase the app.

Utilize social media platforms such as LinkedIn, Twitter, and Facebook to promote your app. Share updates about the development progress, feature releases, and user success stories to engage with your audience and create a sense of community around the "Todo List" application.

Additionally, consider reaching out to tech blogs, industry publications, and online communities related to project management, productivity, and software development. Provide them with press releases, guest articles, or interview opportunities to generate buzz and interest in your application.

Networking with potential collaborators, industry influencers, and like-minded professionals can also help promote your "Todo List" application. Attend relevant conferences, meetups, and webinars, and consider forming partnerships with other software developers or productivity tool providers to expand your reach.
Consider investing in online advertising, such as Google AdWords or social media ads, to reach a broader audience and drive traffic to your website or app store listings.

I'd recommend showcasing the Todo List application on platforms that cater to tech-savvy audiences and early adopters. For instance, showcasing it on GitHub or GitLab would allow developers to access the codebase, provide feedback, and potentially contribute to the project. Additionally, platforms like Product Hunt, BetaList, or Startup List can help generate buzz and attract early users.