The website says this…

“eNuts is in early development. Have a look at the list of known issues before you start using the app. The maintainer is NOT a cryptographer and this work has not been fully reviewed. This means that there is very likely a fatal flaw somewhere. Please be aware that there may be unknown bugs, errors, and incomplete features that could cause unexpected behavior or loss of data. Read more.”

And this…

“eNuts has been temporarily removed from the App Store due to a technical issue.”

This is concerning.