Kana refers to the two syllabic writing systems used in Japanese: Hiragana and Katakana.
Kana Pro is a quiz type learning tool for memorizing the kana characters. There is no "the right way" to use Kana Pro. If you are a beginner, you might want to start by choosing the first two groups (a -> ko) of hiragana. Once you manage to pass the last stage, add in one or two more groups. Aim for the perfection - you want to be answering quickly.
This app is - and always will be - open source, and completely free for personal and educational use.
Have fun!
Updates
6 December 2019 · Enhancement: Improved progressive web app features for better mobile usability & reliability. 2 October 2018 · New feature: Created new groups for katakana characters that look similar. Thanks to sirati97 and Sinbu! 9 September 2018 · New feature: Alternative characters are now separated to groups. Thanks to nahive for his contribution! 29 April 2017 · New domain! Also added comment box and some social media links, share if you like! 27 March 2017 · Bugfix: Allow mobile browsers to change a locked stage number. 24 March 2017 · Enhancement: Improved mobile browser usability with reduced margins. 18 March 2017 · Bugfix: Fixed unintended behavior when same group was selected from both hiragana & katakana. Thanks for the bug report!
Coders needed! This app is open source, but I'm currently the only one working on it. If you'd like to practice your React.js skills, feel free to check the issues and fork it on GitHub!
14 Aug 2016 · Launch: Here we are finally with a new version of Kana Quiz. This app doesn't require flash anymore, and should work great with mobile phones and tablets. Note that this is still a beta version, so there may be a few quirks. I would love to hear your thoughts, so if you'd like, be sure to shoot me some feedback! If you for some reason want to use the old version, it's still available here.