JSFiddle - React, Tailwind, and code Playground

HTML

<div ng-app='MyModule' ng-controller='MyController'>
    <div ng-repeat='activity in activities'>
        <span>{{activity.name}} seen = {{activity.seen}}</span>
        <button ng-click='activity.seen = !activity.seen'>{{activity.seen == true ? 'Mark unread' : 'Mark read'}}</button>
    </div>
        
</div>

JavaScript

angular.module('MyModule', [])

.controller( 'MyController', function($scope){
    
    $scope.activities = [
        { seen: true, name: 'darts' },
        { seen: false, name: 'pool' },
        { seen: true, name: 'cricket' }
    ];
});