I have so many but one of the first apps that I always install on a new device or after reformat is smart taskbar (pro.) I changed the activation settings so that the trigger mode is off so it's only activated from the notification bar. It's kind of like an app drawer you can open from your notification bar (or set up trigger area) so you can launch any app without going to the home screen or app drawer. You can add shortcuts (like settings, contacts, bookmarks etc,) you can open widgets, when you long press on any app you can go to the apps settings page, one click uninstall, edit the app name and add it to one of your labels (categories), access recent & running apps where you can kill the app with the pro version. You can assign labels that are like the categories you have in custom launchers and there's a quick launch spot on top. You can also change the theme if it doesn't look right on your phone or tablet and you can change the transparency...
Obviously I'm crazy about this app, I've been using it for years and I can't imagine Android without it. The developer has made a newer version called smart taskbar 2 but I haven't tried it out since I have the original version set up exactly the way I want it.