Feedback on Front-End Projects?

Hello everybody. I’m wondering if I could get some feedback on my Front-End projects?

Random Quote Machine:
Markdown Previewer:
Drum Machine:
JavaScript Calculator:
Pomodoro Clock:


-They’re all coded in React. I didn’t use any of the other front-end libraries.
-They pass all of the tests. (I am getting some speed flags on Quote Machine & Pomodoro Clock.)
-The Drum Machine & the Calculator uses different files for components. (I couldn’t quite figure it out for the other 3.)
-The Calculator might crash if you do unexpected things with 0s. (I spent a lot of time trying to figure it out but it felt like I was procrastinating so I stopped.)