Snapchat seems to be having an issue right now. You might want to just give it some time and try again tomorrow.
Try searching for the app online instead. I was having the same issue with Snapchat and Facebook, but when I Googled it and downloaded from there where it redirected me to the Apple Store, it worked
I've tried downloading snapchat I turned off my phone rebooted everything it's still not working.
Im also having the same problem with my whatsapp
Somebody please help me