Every so often, Katecheo asks you one flashcard question. On your Mac, the screen stays locked until you answer. On your iPhone, your other apps stay covered until you answer. Greek vocabulary and the Shorter Catechism are built in on both, 500 Bible passages on the iPhone, and your own decks on the Mac.
κατηχέω · to teach by word of mouth
Every so often the Mac locks its screen, or the iPhone covers your apps, with one question. Answer it right and you are back to work.
On the Mac, each right answer stretches the gap before the next question, from 10 minutes up to an hour. A wrong one shortens it. On the iPhone the gap is one interval you set in Settings.
Put focused blocks on a calendar. When a work block starts, only the apps you picked stay open (on the iPhone, when quiet time is on), and on the Mac only the sites you picked too.
Work and rest blocks count down on screen. On the Mac, pausing asks for a reason, and every pause and skip shows in your weekly report.
Katecheo for iPhone counts the minutes you spend on your phone. When they run out, Katecheo covers your other apps until you answer one question. You can also schedule study sessions with an alarm, run a Pomodoro timer that covers distracting apps while you work (quiet time), and study any deck whenever you like.
Pick an interval from 15 minutes of phone use upward, and the apps that always stay open. Phone and FaceTime are never covered.
New Testament Greek vocabulary, the Westminster Shorter Catechism, and 500 key Bible passages in the ESV.
Study any range of a deck whenever you like, in order or shuffled, or drill the cards you miss most.
Coming soon to the App Store
Turn on a built-in deck (New Testament Greek vocabulary or the Westminster Shorter Catechism), or build your own: the app writes a prompt you paste into an AI assistant with your notes, and checks the deck file that comes back before importing it.
Tell the app which week or chapter you are on. Most questions come from there. Older material comes back less often, and the words you miss come back sooner.
The question never comes while you are typing, on a call, or, by default, watching a video. One right answer unlocks the screen.
The gap between questions starts at ten minutes and can grow to an hour, in seven steps. A right first answer moves you up one step. A miss moves you down one. The next question is set by the clock, so closing the lid does not reset it or skip it.
Minutes between questions.
Plan blocks of work and rest on the calendar. When a session is due, the screen locks with a Start button and a five-minute countdown. During a work block, only the apps and sites you allowed stay open. The weekly report shows every planned minute against what you did, including the sessions you missed.
For macOS 15 or later and iOS 26 or later.
On the Mac, no. The question waits until you have stopped typing for a few seconds, and by default never comes while a video is playing, a call is running, or an app is full screen. Music is fine. On the iPhone, a lockout can cover whatever app is open, except Phone, FaceTime and the apps you chose to always allow, so calls still get through.
On the iPhone: New Testament Greek vocabulary, the Westminster Shorter Catechism, and 500 key Bible passages in the ESV. On the Mac: the Greek and catechism decks, plus decks you build from your own notes. The Mac app writes a prompt you paste into Claude, ChatGPT or another assistant with your notes, and checks the deck file that comes back before importing it.
On the Mac, hold Escape for five seconds. Every escape is logged and shows in your weekly report. If you turn on penalty mode in Settings, an escape also shortens the gap before your next question. On the iPhone, a lockout ends when you answer or when you miss all the chances you set, and a missed lockout is logged. You can also turn Lockouts off in Settings, which is logged too.
Katecheo is the Greek κατηχέω, to teach by word of mouth, the root of "catechize."
No. The app makes no network requests. There is no account and no server. Everything stays in a database on your Mac or iPhone. On the Mac you can also save a backup file wherever you like. The privacy policy has the details.