D&D Beyond Maps
7.8#1 in virtual tabletop softwareFrom $2.17 a monthFree planAndroidiOSWeb
VisitD&D Beyond Maps suits D&D groups looking for shared maps, combat encounters, and initiative tracking in a browser. Mobile users should note the stated interface limitations and that trials cannot be started in the app.
You want what its maker publishes above — check its page for the details.