A couple of answers that should work above but this is how i would write it.
Also, i wouldn't declare controllers inside templates. It's better to declare them on your routes imo.
add-text.tpl.html
<div ng-controller="myController">
<form ng-submit="addText(myText)">
<input type="text" placeholder="Let's Go" ng-model="myText">
<button type="submit">Add</button>
</form>
<ul>
<li ng-repeat="text in arrayText">{{ text }}</li>
</ul>
</div>
app.js
(function() {
function myController($scope) {
$scope.arrayText = ['hello', 'world'];
$scope.addText = function(myText) {
$scope.arrayText.push(myText);
};
}
angular.module('app', [])
.controller('myController', myController);
})();