Animer7 will allow you to easily change the animations of multitasking and notifications going to act on their default settings , allowing you to change the appearance of the entry, the fade of the banner, the zoom of the notification and the effect fade out fade with relative .
For multitasking, you can customize the fade instead of appearance of the app open, modify the effect of appearance and the ability to enable or disable the zoom as an animation.
As you can see there are many customizations offered by Animer7 which is why I recommend you try it , you will not be disappointed. You can of course change these parameters in the settings by going to the entry for the tweak as you always do.
If you are interested in trying Animer7 you can go on the BigBoss repo in Cydia and purchase it for $ 1.99, well worth it in my opinion.