Nova Launcher allows you to do things like change the layout, organize your apps better, customize gestures (i.e i have my Camera set to launch with a clockwise twist on my homescreen), adjust icon sizes, tons more things
Tasker lets you set up tasks on your phone in basically whatever way you can think of. If you know what IFTT is, it's like that. You can set up multiple profiles on your phone. Some quick examples are things like connect to Wifi if I am near my home, disable lockscreen if I'm on my home wifi, setting up profiles for different places (i.e at home have volume on, gps off, at work have silent on) basically whatever you can think of doing, it can probably be done