Apps like Katakana Pro

Here are some great alternatives to Katakana Pro by Gerson Luca :
Katakana Dictionary
Katakana Dictionary
★4.8
Fun! Katakana
Fun! Katakana
★4.0
Katakana Memory Hint [English]
Katakana Memory Hint [English]
★4.4
2 Hour Katakana
2 Hour Katakana
★4.6
Japanese Katakana Handwriting
Japanese Katakana Handwriting
★4.5
Japanese characters (PLUS)
Japanese characters (PLUS)
★4.7
Kanana: Easy Hiragana Katakana
Kanana: Easy Hiragana Katakana
★4.2
Learn Hiragana Katakana
Learn Hiragana Katakana
★4.3
Obenkyo
Obenkyo
★4.6
QL Japanese Hiragana/Katakana
QL Japanese Hiragana/Katakana
★4.3
Japanese Kana-Dojo
Japanese Kana-Dojo
★4.5
Japanese characters
Japanese characters
★4.4
Kana Draw (Hiragana Katakana)
Kana Draw (Hiragana Katakana)
★4.5
Learn Japanese-Hiragana-Romaji
Learn Japanese-Hiragana-Romaji
★3.4
Learn Japanese Hiragana
Learn Japanese Hiragana
★4.4
Learn Japanese Katakana!
Learn Japanese Katakana!
★3.9