旧仮名キーボード is a keyboard that allows users to input and convert Japanese text using old-style characters and kana usage. Users can write Japanese text in old-style characters and kana, including characters like "ゐ" and "ゑ" with ease. The app provides various settings for input conversion customization.

On the settings screen, users can control:

• Font Style and Kana Usage: Choose between "old font-old kana," "new font-old kana," and "old font-new kana."
• Character Shape Correction: Opt to make kanji characters' designs resemble old-style characters.
• Writing Style: Select between "general" and "literary style only."
• Special Characters: Choose whether to represent continuous kana with symbols like "ゝ."
• Enlarged Kana: Specify if small characters like "っ" should be enlarged.
• Clear Sound Unification: Decide whether to represent dakuten and handakuten marks or not.
• Katakana Unification: Opt for a unified notation style where kana parts are converted to katakana.

The app supports only flick input for user convenience. For more detailed specifications, users can visit the official website where they can also suggest vocabulary additions for the keyboard.