Hi,
You may looking for ng-class directive, the following example may help you:
<ion-content padding="true">
<ul class="product-list">
<!-- You need a .selected in your stylesheet -->
<li ng-repeat="(key, item) in products" ng-class="{item.selected: selected}">
<div class="list card" ng-click="select_item(key)">
<p><span>{{item.title}}</span></p>
<div class="item item-image">
<img ng-src="{{item.photo}}">
</div>
</div>
</li>
</ul>
</ion-content>
// Your Stylesheet
.selected {
// Highlight style
}
// Your controller
.controller('SomeController', ['$scope', function ($scope) {
// Expects an array, your product list may look like this
$scope.products = [
{ "title": "Super Man's Tommy Toy", "price": 20000, "thumb": "DO_RE_MI.jpg" },
{ "title": "An old picture of Seldom", "price": 1999, "thumb": "MI_RE_DO.gif" }
];
// Your logic for selection, e.g. unselect, select or something
$scope.select_item = function (key) {
if ($scope.products[key]) {
$scope.products[key].selected = true;
}
}
}]);
Hope this can help you, 
[UPDATED] The following links may help you