I love Halloy and it inspired me to make more software in iced_rs, which is a fantastic simple to use UI framework. [0]
The project is even often cited as a good iced_rs code reference repo.
What I like about iced_rs over Qt is that you can write all your code in a single language in whichever style you like. As opposed to Qt which requires you learn an obtuse scripting language (qml) ontop of Cpp and locks performance improvements behind commercial license.
[0] https://iced.rs/