I find Centered to be an incredibly useful tool for getting into flow. It's dastardly good at catching me when I go off task and gently nudges me back to what I was doing. It's like having one of those cartoony angels sitting on my shoulder and smacking me (lovingly) on the side of my head every time I get distracted by a DM or want to "check Twitter real quick".
Strongly recommended!
Raycast