Missing 'Mark as Read' in notifications — universal read-state sync across apps

Missing 'Mark as Read' in notifications — universal read-state sync across apps targets a $5.0B = 500M potential users x $10/year (light-weight notification-sync subscription) total addressable market with low saturation and a year-over-year growth rate of 18% (productivity and personal SaaS tooling adoption rising).

Key trends driving demand: App fragmentation -- more apps + siloed notifications increase user friction and create demand for cross-app solutions.; Decentralized social networks -- new platforms often ship lean clients missing lifecycle features (like mark-as-read), creating openings for third-party solutions.; Privacy-first tooling -- users prefer client-side or encrypted sync solutions, creating differentiation vs cloud-only competitors.; Micro-SaaS monetization -- willingness to pay for narrowly focused tools has increased, supporting subscription pricing..