So finally I had to retire the mobile apps - they were coded in the Actionscript programming language that was getting harder to update with each new version of iOS, and the promise of being able to publish to all platforms had long since faded.

I decided the best way forward was to develop a mobile-suited web app instead, which has a lot of benefits for updating and for use across devices (browsers on iOS & Android, as well as on PCs).  It has a similar but simpler format to the Kanji Connect app, which I have found to be really useful & enjoyable as a way to make you think about the connections between kanji form, readings & meaning.

To record your progress with the kanji & vocab that you study,  just sign up for free with your Google account. :

https://kanjilab.co/

One big nice new feature of this app is the ability to import your own vocab to study! From the profile page, just follow the 'Import Kanji' link and copy-paste in your kanji/reading/meaning rows. Maybe you have some Anki sets, or big lists of saved lookups from dictionary apps, or Jreading webreader add-ons - it's time to actually review them!

I do hope to continue to develop further functionality in future, such as linking to sentence examples, and adding some other game modes - but this depends on how many people use it. So if you like it, let your Japanese-studying friends know about it!

Do you have trouble with big numbers in Japanese? Even quite advanced speakers can often have difficulty due to the different way of counting, with the unit of 'ichiman' = 10,000.
You can practice with these dictation activities (thanks to Quizlet!) at several different levels of difficulty.
http://www.kanjigames.com/number-dictation.html

Try out this HTML5 food game with katakana words!!
Match words/pics to clear a vertical line, against a bot or player:
http://www.phrasebotgames.com/#/acrossndown/146116183

Using the Quizlet Flashcard Website for JSL

Quizlet（www.quizlet.com）は、非常に使いやすく信頼できるフラッシュカード用ウェブサイトで、学生用の無料のiPhoneとAndroidアプリもあります。 長い間、英語使用者にと人気のあるアメリカのウェブサイトでしたが、最近多言語のインターフェイスと指示が追加されたので、更に簡単にどの国の人々も使用することができるようになりました。

Quizlet (www.quizlet.com ) is a very user-friendly and reliable flashcard website that also has free iPhone and Android apps for students. It has long been a popular American website for English speakers, but it has recently added a multilingual interface and instructions so it is now even easier for people from any country to use.

JLPTや「Genki」や「みんなの日本語」といった一般的な教科書など、多くの日本語のリストを含む、何百万件ものフラッシュカードがあります。 フラッシュカードセットには写真を入れることができ、高品質のテキスト読み上げ音声を自動的に提供することもできます。

It has millions of sets of flashcards on any subject, including many Japanese lists for topics such as the JLPT and popular textbooks like ‘Genki’ and ‘Minna no Nihongo’. The flashcard sets can include pictures and automatically provide high-quality text-to-speech audio.

既存のリストをそのまま使用することも、コピーして編集することもできます。 また、スプレッドシートのデータを入力またはコピーして自分で作成することもできます。 フラッシュカードはすべて両面フォーマットであるため、通常、漢字は反対側の意味と読み方（および任意の画像）の両方に表示されます。

You can use the existing lists as they are, or copy and edit them. You can also make your own, by typing or copy-pasting spreadsheet data. Flashcards are all in 2-sided format, so the kanji would usually go on one side and both the meaning and reading (and optional picture) on the other side.

クイズレットのユーザーアカウントにはユーザー名「kanjigames」で多くの日本語と英語の良い和英語のリストがあります。
https://quizlet.com/kanjigames/folders

You can find many good Japanese-English lists of words and phrases on my Quizlet user account with the username ‘kanjigames’:
https://quizlet.com/kanjigames/folders

以下は、リストを使用できるアクティビティの一部です:

1. フラッシュカード - 一度にすべての情報を表示するか、片面を表示してから別の面を表示するかを選択できます。 困難な項目のサブセットを集中的に実践するには黄色い星印を付けてこれらの項目を別々に調べることができます。
2. Learn - 答えを入力します。 「設定」では、プロンプトとアンサーが漢字、英語、ひらがなのいずれかを選択できます。
3. マッチ - いくつかのフラッシュカードの質問と回答が表示され、ユーザーは一致する必要があります。
4. ライブ - 教師がクラスを設定している場合、クラスでクイズゲームを行うことができます（最低6人のプレイヤー）。

These are some of the activities that you can use the lists with:

1. Flashcards - you can choose to show all information at once, or show one side and then the other. For focused practice of a subset of difficult items, you can mark them with a yellow star, and these items can then be studied separately.　　　　　　　　 
2. Learn - You type the answer. In ‘Settings’, you can choose whether the prompt and answer are the kanji, English or hiragana reading.　　　　　　　　　　　　　　　
3. Match - both questions and answers for some of the flashcards are shown, and the user has to match them.　　　　　　　　　　　　　　　　　　　　　　　　　　
4. Live - If a teacher has set up a class, they can hold a quiz game in their class (minimum 6 players).　　　　　　　　　　　　　　　　　　　　　　　　　　　　

生徒の参加可能なクラスを作成できる教師のアカウントを無料設定することができます。 次に、有料のウプグレードをすればクラス/学生/設定の進捗状況をある程度把握もできます。
You can set up a free teacher’s account and create classes with assigned flashcard sets which your students can join. If you upgrade to a paid account you can also monitor class/student/set progress in the following ways:

フラッシュカードセットでは、アイテムが正しいか間違っているかをパーセンテージで表示し、効率的にレビューすることが簡単にできます。
On flashcard sets, you can see the percentage of times items are gotten correct or mistaken by the class as a whole, making it easier to review efficiently.

また、与えられたフラッシュカードセットの様々なタイプのアクティビティをどの生徒が完了したかを見ることができ、クイズレット学習を宿題として設定することができます。 ただし生徒のアクティビティの結果を確認することはできますが、使用されたモード（英語、漢字、ひらがななど）の表示方法はわかりません。
You can also see which students have completed the different types of activity for a given flashcard set, making it possible to set Quizlet study as a homework activity. N.B. Although you can see a student’s results for an activity, you cannot see which mode was used (e.g. whether the user had to answer with English, kanji or hiragana).

クイズレットフラッシュカードセットを使用するその他のアクティビティ
(Other Activities Using Quizlet Flashcard Sets)

PhraseBot App

クイズレットフラッシュカードセットは、無料のフレーズブロットアプリ（www.phrasebotapp.com）にインポートすることもできます。これはよりゲーム的であり、クイズレットが提供していない進行状況の追跡やさまざまな種類のモードを提供します。例えば、単語を個々の漢字/ かななどです。

Quizlet flashcard sets can also be imported into the free PhraseBot app (www.phrasebotapp.com) , which is more game-like and offers progress tracking and different kinds of modes not provided by Quizlet, such as breaking up words into individual kanji/kana.

HTML5 Games

また、キズレットのフラッシュカードセットのID番号（セットのURLに表示されている最後の文字列（例：https://quizlet.com/211795668）を使用して、いくつかのKanjiGames HTML5ゲーム（http://www.kanjigames.com/html5-games.html) も使用可能です。

They can also be used in several HTML5 games on the Kanji Games website (http://www.kanjigames.com/html5-games.html ) by using the Quizlet flashcard set ID number (the last string of numbers seen in the set’s URL e.g. https://quizlet.com/211795668)

クイズレットや漢字ゲームのウェブサイトやアプリの使い方についてご質問がありましたらお気軽にお問い合わせください。こちらはQuizletのウェブサイトで日本語でもっと細かい説明があります。
https://quizlet.com/ja/teachers　​

Feel free to get in touch if you have any questions about how to use Quizlet or the Kanji Games websites or apps!
Further information on the Quizlet website for teachers (in Japanese):
https://quizlet.com/ja/teachers　​

The free PhraseBot app (www.phrasebotapp.com) offers different kinds of practice and progress tracking with sets of flashcards imported from the Quizlet website (www.quizlet.com).

There are already many sets of Japanese flashcards for JLPT and various textbooks on Quizlet - and you can also easily make your own by inputting your data or uploading a spreadsheet.

I have lots of good sets on my kanjigames account on Quizlet which you can feel free to use:
https://quizlet.com/kanjigames

You can use single kanji, compounds or even sentences in PhraseBot - here's just one screenshot example using a set featuring common name kanji:

How to import sets from Quizlet

1) From the main screen, go to the Quizlet Sets screen and tap the magnifying glass button to go to the 'Quizlet Search' screen.

A very nice source of practice for beginning readers of Japanese is the 'Watanoshii Free Web Magazine in Simple Japanese':

http://watanoc.com/

​​It has hundreds of articles with mouse-over word translations and full text translations available. Some articles also have good quality audio as well.  Highly recommended for JLPT N5/N4 learners!

For not just learning about grammar, but also getting some practice putting together sentences, the Wasabi website has some nice online activities!

For each grammar point there are a bunch of sentences given for you to translate, and you can tap the answer field to see the answer (works fine on smartphones too).

You can also do this activity aurally, playing a soundfile to hear the prompts and answers.

Try it out here:

https://www.wasabi-jpn.com/japanese-lessons/japanese-grammar-with-instantaneous-composition-method/

How well do you know the prefectures of Japan? Try this HTML5 quiz, cued with the map and English translation, to find the prefecture name in kanji: ​http://www.phrasebotgames.com/#/quizgame/82785726