I would advise installing Xposed Framework. Xposed Framework enables to tweak your ROM in all sorts of ways without the need to flash a new one and possibly brick your device. There are many applications you can use once you've installed the framework, and you can find all of those apps here.
I'm assuming you already have SuperSU installed?
Once you get used to its layout, Tasker is an amazing app. Titanium Backup is one you'll also want to get your hands on.
I misread OP post.
AdAway - Removes ads.
Root Booster - Change CPU governor to either save battery or overclock.
Xposed Installer - Can be dangerous to install, but cool if fully installed.
Flashify - Good for flashing different recovery images.
Lucky Patcher - Doing LVL and In-App Emulation Hack.
Game Hacker - Cheat in offline games.
ROM Toolbox Pro - Customize your ROM.
WiFiKill - Hack your internet.