Implement notification system, which does not exist on other existing platforms.
possible simplified flow: user defines aoi and search params (providers selection, settings etc) and enables notifications. Then query is performed server-side, and the user receives one of weekly notifications, or as soon as result appears.
Would require user accounts and db and not be purely client-side. Or store user searches and let user access it when connecting to the UI to see if there is anything new.
Implement notification system, which does not exist on other existing platforms.