What is stored on your phone
Rightly ships with the full text of the Berean Standard Bible, the Hebrew Old Testament (Westminster Leningrad Codex) and the Greek New Testament (SBL edition) with their word-by-word tagging, the interlinear that links them to the English, and the lexicons: the unabridged Brown-Driver-Briggs, Thayer’s, and Strong’s Hebrew and Greek dictionaries.
Because all of that is on the device, tapping a word does not wait on a server. The word sheet opens immediately, whether you have five bars or none (what the word sheet shows).
Notes are saved locally first
When you write a note or highlight a verse, it is saved on your phone straight away. If you are signed in, it syncs to your other devices the next time you are online. If the same note was edited in two places, the most recent edit is kept.
What needs a connection
Signing in and syncing need the internet, of course. Commentaries load when you open them, and the passages you have opened recently stay on the phone, so a commentary you read this morning is still there on the plane this afternoon (which commentaries are included).
Why offline matters
Bible study happens in places with bad reception: church buildings, retreat centres, rural congregations, flights, and countries where mobile data is expensive. A study tool that stops working there is not much of a study tool. Keeping the text and the tools on the device also means your reading is not sent anywhere while you read.