What I use to organise the right sliced assets into their properly named folders.

Export_assets.sh

# Android export

mkdir xxhdpi; mkdir xhdpi; mkdir hdpi; mkdir mdpi; mkdir xxxhdpi

for file in $(find . -type f -iname '*-xxhdpi*'); do
  mv "$file" "xxhdpi/${file/-xxhdpi/}"
done
for file in $(find . -type f -iname '*-xhdpi*'); do
  mv "$file" "xhdpi/${file/-xhdpi/}"
done
for file in $(find . -type f -iname '*-hdpi*'); do
  mv "$file" "hdpi/${file/-hdpi/}"
done
for file in $(find . -type f -iname '*-mdpi*'); do
  mv "$file" "mdpi/${file/-mdpi/}"
done
for file in $(find . -type f -iname '*-xxxhdpi*'); do
  mv "$file" "xxxhdpi/${file/-xxxhdpi/}"
done


# iOS export
mkdir @3x; mkdir @2x

for file in $(find . -type f -iname '*@2x*'); do
  mv "$file" "@2x/${file/@2x/}"
done
for file in $(find . -type f -iname '*@3x*'); do
  mv "$file" "@3x/${file/@3x/}"
done