Does a camera dictionary work without an internet connection?
It depends entirely on where the dictionary lives. Apps that send the recognised word to a server need a connection for every lookup; apps that bundle the dictionary work anywhere. The download size gives it away — a full English dictionary is well over a hundred megabytes, so a 30 MB app is almost certainly calling out to something.
Text recognition itself is usually on-device on modern iPhones and is not the constraint. The constraint is the dictionary data.
Booktionary includes English definitions. Additional dictionaries and English-word translation packs are separate optional downloads. The upcoming language expansion expands this selection to 24 book languages and 24 translation targets; see the home page for the list and release availability. After installation, recognition and lookups run on the phone and work offline. Internet is needed for the catalog and selected downloads; lookup words and camera images are not sent.
There is no account, history, sync or analytics. Optional pack requests go to booktionary.io; the hosting provider's security logging is described in the Privacy Policy.