Andy,
You can use the DI container to store your class and then use it from wherever you want in your application. So for instance let's say that you have this class:
class Utils
{
public function translate($string) {...}
public function encode($string) {...}
public function decode($string) {...}
}
in your bootstrap you will register this as a service
$di->set(
'utils',
function () {
return new Utils();
}
);
Then from any controller you can do then:
$newValue = $this->utils->translate($oldValue);
If you need to access the service in models you can use the
$utils = \Phalcon\Di::getDefault()->get('utils');