Terms of use

Your use of Ostraka is governed by Apple’s Licensed Application End User License Agreement (the Standard EULA). These terms add the details of Ostraka Pro. Effective 25 October 2026.

Ostraka is free to download. Free: Units 1 and 2 (letters, sounds, the article and the first declensions, with their lessons, practice and readings), the first six Aesop fables, two short New Testament letters, two games (Alphabet Sprint and Word Match), daily review, and the dictionary with word cards everywhere. Ostraka Pro opens everything else.

• Ostraka Pro weekly: $2.99 a week.
• Ostraka Pro monthly: $7.99 a month.
• Ostraka Pro annual: $39.99 a year, with a one-week free trial for new subscribers.
• Ostraka Pro lifetime: $79.99, a single purchase that never expires.

These are US prices. Local prices are set by the App Store and shown in the app before you buy.

• Payment is charged to your Apple Account when you confirm the purchase, or when the free trial ends.
• A subscription renews automatically at the same length and price unless it is cancelled at least 24 hours before the end of the current period. Your account is charged for the renewal within the 24 hours before the period ends.
• Manage or cancel subscriptions in your Apple Account settings. Cancelling stops the next renewal; Pro stays active until the period ends.
• Any unused part of a free trial is forfeited when you buy a subscription.
• Payments and refunds are handled by Apple under its terms; refunds are requested at reportaproblem.apple.com.

Ostraka’s lessons, exercises and graded readings are © 2026 Burak Gökyüz. The Greek texts, the lexicon and the annotations come from open scholarship and are shared under Creative Commons Attribution-ShareAlike 4.0:

• Perseus Digital Library, Tufts University: Greek texts and the Liddell–Scott–Jones lexicon (CC BY-SA 4.0);
• Lyceum (lyceum.quest): annotated Aesop, Xenophon, Plato, the New Testament and Marcus Aurelius, with glosses and translations, many AI-assisted (CC BY-SA 4.0);
• Diogenes and Morpheus: the morphological analyses (CC BY-SA);
• the Ancient Greek Dependency Treebank: the annotated Homer (CC BY-SA);
• Wiktionary: supplementary definitions and etymologies (CC BY-SA).

The app’s lexicon and annotated texts, derived from these, are shared under the same licence. Every source is credited in the app under Me → Settings → Sources & credits.

Gentium Book Plus (SIL International), GFS Didot (Greek Font Society) and EB Garamond (The EB Garamond Project Authors) are used under the SIL Open Font License 1.1. This website uses subsets of EB Garamond and Gentium Book Plus; licences: EB Garamond, Gentium Book Plus.

Forms, parses and paradigms are checked against the morphology database, and the lessons are written with care, but Ostraka is a learning tool and can contain mistakes. Please report any to brkgkyz@gmail.com.

Burak Gökyüz, brkgkyz@gmail.com.