This is my personal choice for productivity tools, you may find these tools usefull but you may also find differently. I use ubuntu desktop and android phone, so my personal choices will based on these platforms.
Tea Time (Ubuntu)
Link package here, github here. A rather simple timer, if you wanted to say do pomodoro I personally think this tools will fit just fine. However it does not have an automatic pomodoro scheduler, so you have to manually click “start timer” everytime.
White Noises - Spotify
Since the family package subscription is quite cheap (around ~$7 at Indonesia) I use spotify to listen to music or to listen white noises while I work. Strangely I found myself choosing cricket sound at night, like this one, probably because it simulate quite night sound perfectly.