JA Sensei 4.5.1 has been released:

• Lessons: 5 new lessons free for Premium users!
• Lessons: customize the example sentences to meet your needs (display furigana/romaji, space out words)
• Minor fixes (uppercase during quizzes, text truncated on some buttons, etc.)

For PREMIUM users, please reinstall the Vocabulary and Lesson modules (you won't lose your stats or lists).

Update your application on Google Play.