SIGIL is a personal tool for iPhone and iPad, provided as-is for your own use.
SIGIL turns a short phrase you type into a circular graphic mark, and turns that mark back into the phrase, on your device. An open mark is readable by any SIGIL user. A circle mark is readable by anyone holding that circle's key, which you exchange yourself, outside the app. Whoever holds a circle's key can both read and write in it; if you hand a key to someone, you have handed them the room.
SIGIL is not a secure-messaging product and must not be relied on as one. It uses the platform's own cryptography, but the security of anything you write depends entirely on who you gave the key to and how you gave it. Do not use SIGIL to protect information whose exposure would cause you serious harm. It is also not a messenger, a social network or a backup service.
You are responsible for the phrases you encode and the images you share. Do not use SIGIL to send anything unlawful, or to harass, threaten or deceive anyone. We cannot read what you write and therefore cannot moderate it; that is the design, and the responsibility follows it to you.
Keys are stored on your device and nowhere else. We hold no copy and there is no recovery path through us. Export and back up your keys; it is free in the app at every tier and always available.
SIGIL Premium is offered as an auto-renewing monthly subscription ($3.99/month) or annual subscription ($24.99/year, with a 7-day free trial for new subscribers), and as a one-time Lifetime purchase ($49.99, family-shareable), all billed through your Apple ID. Subscriptions renew unless cancelled at least 24 hours before the current period ends; manage or cancel them in Settings → Apple ID → Subscriptions. The free tier remains fully functional regardless of any purchase: reading open marks is never limited, your first circle is never limited, and the marks it draws are identical in quality to the paid ones.
The phrases you write and the marks they produce are yours and stay on your device. Hadger claims no rights over them.