Whatsapp: This app is for all ages in the modern era, due to comunication features with families.
Youtube: This app is for all ages and genders as well, due to the knowledge and entertainment you can get from watching videos.
Spotify: Directed to both teenagers and adults, for them to listen music while driving or studying.
Uber: I think this app is more for teenagers and young adults who have complications on getting to different places due to their accesibility to transports.
Netflix: Directed to all the people who wants to watch their favorite movies or series, but dont have a TV in that precise moment.
8 Ball Pool: App created for pool lovers, who simply don't dispose of a pool table to play in their homes.
Waze: App designed for all drivers that don't the exact location of their destinations.
Bancomer Movil: App for those who dispose a Bancomer Account, for them to manage from their cellphones.
Microsoft Outlook: App for the people who like to work a lot, and for the people who need to get a work done and don't dispose of a computer in that certain moment.
Super Mario Run: This is an app for the people who like Mario games since childrens, and for those who are searching for an entertaining game to play.
Clash Royale: For the people who are searching for the best games out there in the store, and want an addicting game.
Some apps that are in my opinion, easy to use, are Whatsapp and Snapchat. In whatsapp, you have an easy access to all your chats, and you can look for a specific chat quite easily. In snapchat you can also do so many things and access different menus in just one click.
On the other hand, Twitter is a more complex app to use, due to all the configuration menus and settings you can choose. There are also many restrictions that you can manage on some menus.