iCloud Data from apps like instagram and snapchat
When you chose what data to back up in your icloud from your iphone, if you don't chose an app, will that app still appear on your new phone when you restore from a backup?
Also, with apps like instagram and snapchat, if you don't choose them, and the app is on your new phone, will all your photos and snapchat memories, etc still be available when you log in? If everything does show up when you log in, what is the purpose of chosing which data to back up?
Thanks in advance for your answers!