I just got my first android device 2 days ago and I'm learning all the things about this system, as I've only used iOS and BBOS before. I'm loving the keyone for sure but I find it annoying that if I download some memes online or on 9gag, the photos cant be automatically saved on my SD card. The internal storage is a bit small imo.
You can't, by design apps cannot be on external storage. Unless you format the card as internal storage, but it's risky. If the card ever fails you'll need to hard reset your phone, since your entire logical storage is toast.