Ballistics
Saving a field card stores the exact inputs and results at that moment. The card never changes afterwards, even if you edit the profile, load or zero it came from. If your data changes, save a new card.
Saved cards are cached on the device you are using, for your account only. Sign out and that cache is cleared.
Offline reading works once a card and the app have been opened on that device while you had signal. Open your cards at home before a trip and they will be there in the field; a card you have never viewed on that phone may not load with no connection.
Any saved card can be exported as an image or a printable A4 PDF. Both are produced from the stored snapshot — nothing is recalculated, so the paper matches the card exactly.