App install sizes - internal storage vs SD card

[mathewhayward]

I've just bought an SD card to stick in my Lumia and I've noticed that app sizes are greatly increased when moving to the SD card. For instance, one app when installed on the internal storage is 39MB. Once moved to the SD card, it's 111MB. Is this normal?

I've searched a bit about this and I can't find any definitive information on it.