AssistantLove helps Spotify Premium Subscriber to get into their gigantic music library in Spotify, of course with Siri, then pick your already selected favorite tracks to listen to.
After you installed it and then turn the Spotify integration ON, you will then dictate Siri to play a certain song or artist, it will then play your song.
And as for GPS integration feature this tweak provides will give you ability to pick your favotire GPS application to use with Apple's digital assistant. And GPS navigation software that this tweak supports are Waze, MotionX-GPS, TomTom, Navigon and more. Just say the a certain place / location you will like to go, Siri will show you the direction right away!
There is another worth exposing feature which is creating aliases name for your app when you are about to launch it. Let's say you a have Battlefield 3 game installed on your device, you can simply say the Battlefield to launch the game.
AssistantLove can be configured in your Settings.app to toggle some features, or turn it off feature if you don't need it. And it's not a free tweak, its price $1.99 and currently available in Cydia under BigBoss repository.