You can add this page to your iphone or ipad Home screen (use safari menu) and then encrypt and decrypt messages without internet access.
Adding bookmarklet is a little bit tricky on apple devices, due to iOS limitations. To do this, please follow the next steps:
Tap here - this will change page title and append bookmarklet into address bar
Select Add Bookmark
Tap the Bookmarks button
Locate just created Encipher.It bookmark in the list.
Tap Edit and then tap on the bookmark
Tap in the second field (it begins with 'http').You want to edit the beginning of this text, so tap and drag the loupe all the way to the left.
Place the editing point between the "#" and the "j" then delete all to the beginning of the line