Browser extensions win when they add one small, instant utility to a page the user already visits daily. StartSeed generates ideas scoped to one browser action, one user moment and one freemium or paid model.
A meeting-cost tracker that calculates the hourly burn rate of every calendar invite based on attendees' estimated salaries. Free with a Pro plan at $3/month for team dashboards. It could be called Burnrate.
A reader-mode toggle for recipe blogs that strips ads, popups and life stories, leaving only ingredients and steps. One-time purchase at $2.99. It could be called JustCook.
An auto-coupon finder that scans the current checkout page, tests known codes and applies the best one silently. Takes 1% affiliate commission on savings. It could be called Snipcart.
Ship the smallest version that solves one annoyance. If users install it and keep it enabled for a week, you have a keeper.
A daily annoyance, a one-click fix, and a user base that's already on the sites where the extension adds value.
Yes — freemium upgrades, affiliate commissions, or a one-time paid tier all work. Avoid selling user data; it kills trust and store approval.