Korean study aids

Below are some items I've found useful as a student of the King Sejong Institute

The King Sejong Institute Foundation has an e-book version of their textbooks, including the Sejong Korean Conversation (세종한국어 회화) series available to be viewed online (but not downloaded or printed) at their website:

https://nuri.iksi.or.kr/front/main/main.do 

Further details here

The Sejong Korean (세종한국어) textbooks are also available online:

Two other Sejong Institute apps can be downloaded and are partially functional offline. 

The "Sejong Korean Conversation - Basic" app (Android; iPhone) is a supplement for Sejong Korean Conversation 1 (세종한국어 회화 1). The icon looks like this:

This app offers some help in practicing dialogs but doesn't have all the vocabulary from the Sejong Korean Conversation 1 book. 

The "Sejong Korean Vocabulary" app ("Beginner·Intermediate" for Android; "Sejong Korean Vocab - Basic" for iPhone) introduces vocabulary from the Sejong Korean 1 (세종한국어1) textbook, & should be very useful if you use that book. The icon looks like this:

On my Android, the icon for the app looks like this:

After the app is open, you can go to "search", then "search by volume" & chapter. What looks useful: 

• the dictionary citation form with English translation
• example sentences with appropriate conjugations 
• "collocations" (frequently occurring expressions) 
• a recorded pronunciation of the vocab. item as well as the example sentence
• the opportunity to record one's own voice & compare it to a native speaker
• the opportunity to trace the word

This app also has a searchable index as well as other functions not connected to each lesson. Although the search function works offline, unfortunately you can't copy & paste to another app.

Not related to King Sejong Institute materials:

Papago 

• Seems more reliable for Korean translations than Google translate. But beware.
• The Papago smartphone app does a good job of capturing Korean from images and offers speech input, among other options. 
• The web version of Papago has an "Autocomplete" function and also provides definitions of individual words and the relevant Hanja; when you highlight an individual word, it links to the entry in the Naver online dictionary and also provides conjugations.

Dictionaries & Reference sites

• English Korean Dictionary (for Android) is very basic but works offline.
• Rieul Korean (for Android) requires internet access but links to app versions of Daum and Naver, and will often return results for conjugated verbs & adjectives. They also show Hanja.  
• wiktionary provides reliable verb conjugations, but searches must be based on the citation form. After entering the citation form, scroll down to "Conjugation" & click on "show". The site also shows the verb's etymology, pronunciation, part of speech, and a brief definition
• koreanverb.app is less reliable, but will usually display the dictionary citation form by reverse look-up. Click on an entry to show romanization, pronunciation and formation of the conjugation
• mirinae.io analyses the grammar of any Korean text typed into it, and if you click on a particular expression, will give a detailed explanation. (Note the translations of sentences and individual words are not  always reliable).

The downloadable anki app available at apps.ankiweb.net

• There are versions available for Windows, Mac, & Linux. For Android users, the AnkiDroid app is free, but to use this app on an Iphone you need to buy the AnkiMobile app.
• Useful for learning & memorizing new grammar or vocabulary & improving listening comprehension. 
• After signing up & downloading the app, you can make up your own flash cards, or use the two excellent "decks" of flashcards developed by Evita at ankiweb.net/shared/decks/korean: "Korean Grammar Sentences" & "Korean Vocabulary". 
• I made flashcards of the vocabulary in some of the Sejong Korean Conversation (세종한국어 회화) books. See Sejong Korean Conversation 1-3 (세종한국어 회화 1-3) vocabulary flashcards
• Most of the flashcards have audio & all are functional offline.

"Korean Grammar Sentences" starts with simple sentences & works its way up. Flashcards introducing new grammar typically offer simple explanations:

The "Korean Vocabulary" deck may display hanja, but for that's for reference only: 

If you want to be able to not only hear how something is pronounced (as in Google Translate or Papago), but also download the audio file, there are sites like https://ttsmp3.com/text-to-speech/Korean/ where you can enter text in Hangul & have a voice read it out & save it to your device. But even in sentences ending with a question mark, it currently can't provide a rising intonation.
If you want to further edit audio files (including slowing them without lowering the pitch), you can download Audacity.

Please feel free to offer comments, suggestions, or questions below.