The ability to create both iOS and Android applications and deploy them to multiple platforms with just one code base. It's easy to use and the support team is amazing! I would like more flexibility when it comes to creating custom widgets for my app. For example, if I want to show an image from a URL, I have to copy/paste the entire URL into the widget code. This can be done in other platforms but not Harmony. Also, there are some bugs that need to be addressed. Some features don't work as expected. We are solving the problem of having to develop separate applications for iOS and Android.