13) STRETCH APPS TO FIT THE SCREEN
An 18:9 aspect ratio is great and all, but not everything available in the Google Play store won't fill all that space - leaving ugly black bars that defeat the object of a longer, skinnier screen. Good job you can stretch everything to fit, then.
Head to Settings > Apps > Full screen apps, and you'll be able to choose from 16:9 and 18:9 ratios. Some apps work better when stretched out than others, so you'll have to experiment, but you can set the ones that work to default to one ratio or the other without having to faff every time.
14) DOUBLE UP WITH PARALLEL APPS
It's less of a big deal here in the UK, where our favourite apps like Facebook, Twitter and Instagram all have multiple account switching built-in, but Parallel Apps makes things a lot easier if you do have something that won't let you log in to several accounts at once.
Head to Settings > Apps > Parallel apps and you can choose which of your apps you want to duplicate. Not everything works, but chat apps are pretty well supported. Tap to choose the ones you want, and the Parallel one gets added to your app drawer.