For years I studied on Study Together servers with a Pomodoro timer running. The timer helped, but on low days nothing pulled me back for "just one more session". Counting minutes wasn't enough. I wanted something to show for them.
So I've been building a focus timer for Windows where your work looks after tiny pets on your taskbar. Your pet naps beside you during a focus round, finished rounds earn coins for its food and toys, and an idle PC earns nothing. There's also a private Friends group that shows who focused most each week.