Stellar Vocab
Stellar Vocab is our vocabulary app for iPhone. It scores how well the learner knows each word from 0 to 100, and it uses those scores to choose new words just beyond the learner's vocabulary and to bring back words that need review. It is for anyone building an English vocabulary, including students preparing for the GRE, SAT, TOEFL or IELTS.
Activities
Each word moves through six levels of activity, from meeting the word to using it in the learner's own sentences. A word's score is capped until the learner answers correctly at the harder levels, so recognizing a word never counts as mastering it.
Meet the word
Definition, examples and the word said aloud.
Pick the meaning
Recognize the word among close choices.
Match
Pair words with meanings and synonyms.
Fill the gap
Choose the word that fits a real sentence.
Spell it and build
Spell the word, then put a sentence with it in order.
Write it yourself
Use the word in your own sentence, graded by AI.
Mastery
Each word has a score from 0 to 100, in four bands. Right answers raise the score and wrong answers lower it. The score also falls slowly while a word goes unpracticed, which brings the word back for review. A word reaches Mastered only after the learner uses it correctly in their own sentences on two different days.
- New0-24
- Learning25-69
- Strong70-89
- Mastered90-100
Daily practice
Review depends on regular practice, so the app is built around a daily session of about 12 minutes, with 8 new words and 14 reviews. A streak counts the days in a row with a session, and one missed day a week does not end it. A Daily Word from the learner's own library gives one word to use that day. Circles are private groups, joined with an invite code, that compare weekly XP.
Word score
The word score adds up the mastery of every word in the library. Harder words count for more, so the score reflects both the size and the depth of a vocabulary.
AI grading
With the learner's consent, AI grades the sentences they write or say for correct use of the word.
Word packs
Topic packs add words in areas such as health, law and science. Test packs cover the GRE, SAT and TOEFL / IELTS. Learners can also add their own words.
Natural voice
Every word is spoken in one neural voice. Learners can say a word and check their own pronunciation.