# ECG Builder โ€” 12-lead ECGs for teaching > 12-lead ECGs for teaching (iPhone/iPad app by Mark Daniel Figueroa.) - Source: https://appshunter.io/ios/app/ecg-builder/id6809634568 (this page in markdown: same URL + `.md`) - Developer: [Mark Daniel Figueroa](https://appshunter.io/developer/1890265406) - Category: Medical, Education - Price: Free with in-app purchases - Age rating: 17+ - Requires: iOS 17.0 ยท 9 MB - Languages: American English - Released: 2026-09-20 - Data updated: 2026-09-22 - User reviews in markdown: https://appshunter.io/ios/app/ecg-builder/id6809634568/reviews.md ## What is ECG Builder? Draw any 12-lead ECG in seconds. Describe it in plain words or build it tool by tool, then export it for your slide, handout or exam. DESCRIBE IT AND IT DRAWS "Inferior STEMI at 52 with reciprocal change." "Atrial fibrillation with RVR at 140." "LBBB with a paced rhythm." The sheet prints onto real millimetre paper, left to right, the way a recorder does. OR BUILD IT BY HAND Eleven tools, one question each: - Rhythm, Rate, Intervals - Conduction, Ischaemia, Repolarisation - Chambers, Ectopy, Pacing - Syndromes, Sequence NOT A LIBRARY OF PICTURES Every tracing comes out of a physiologic model, so the findings agree with each other. - Add inferior ST elevation and the reciprocal depression appears in aVL by itself - Drag the rate under 60 and sinus rhythm relabels itself sinus bradycardia - Pace the ventricle and the spike projects onto all twelve leads, with the right polarity in each WHAT IS IN IT - 26 rhythms, sinus arrhythmia through torsades to asystole - 21 named patterns in one tap: Wellens A and B, de Winter, Brugada 1 and 2, S1Q3T3, pericarditis, early repolarisation, hypothermia, digoxin, hyperkalaemia, LVH with strain, long QT and more - Sequence: the rhythm changes partway through the strip, with a shock where you want it - 5 layouts, including 3x4 with a rhythm strip and a stacked layout for the phone - 4 papers, thermal cream to defibrillator monitor - 25 or 50 mm/s, 10 mm/mV. Hold a ruler to the screen and the intervals measure correctly - Baseline drift, muscle tremor and mains hum, each on its own slider - A patient header the way a machine prints it: name, age, sex, rate, rhythm, date and time. All of it yours to set, all of it fictional TEACHING BOARD (IPAD) - Hide the tools and the sheet becomes a board - Draw on it with Apple Pencil. Marks stay on their beats at any zoom - The frontal axis wheel and the chest lead map sit beside it, each with room for the pen - Play runs all twelve leads live at the speed printed on the sheet - Record the screen while you teach and send the video to your students - Save the board as a Letter handout EXPORT - PNG for a slide - Vector PDF at true physical size, still measurable with a ruler once printed - Yours to use in slides, handouts, exams and question banks, including commercially FREE AND PRO Free builds a normal twelve-lead and will show you any other one. Ask for torsades de pointes and you get torsades de pointes, drawn in full, as a watermarked preview you can read but not edit or export. ECG Builder Pro is one purchase, not a subscription, and it covers Family Sharing. It unlocks every rhythm and every finding to edit, rolls a new patient with the same diagnosis, and lets the sheet leave the app clean. No account, no sign-in, no network. The app works in Airplane Mode and nothing you type leaves the device. EDUCATIONAL USE ONLY Every tracing is synthetic, generated. ECG Builder is not a medical device and must not be used for diagnosis, treatment, or any patient-care decision. ECG Builder is a CardioLens product. ## Pricing and in-app purchases Base price: Free. **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | ECG Builder Pro | $24.99 | one-time | ## Version history (last 2 releases) ### 1.1.0 โ€” 2026-09-21 Hide the tools and the sheet becomes a teaching board. Draw on it with Apple Pencil, and your marks stay on the beats you drew them on at any zoom. Two figures sit beside it, the frontal axis wheel and the chest lead map, each with its own space for the pen. Play runs all twelve leads live at the speed printed on the sheet. Record the screen while you teach and send the video straight to your students. Save exports the board as a Letter handout. Every setting the engine has is now a slider or a picker: - Rhythm options: flutter ratio and variable block, VF coarseness, escape focus and rate in complete block, retrograde P, Wenckebach cycle, Mobitz conduction, VT origin, torsades twist, P-wave asystole, sinus pauses - ST slope, extent and reciprocal weighting - T inversion depth, peaking, symmetry and the U wave - QRS amplitude, electrical alternans, P mitrale and P pulmonale - PVC origin and count, atrial ectopics - Pacemaker failure to capture and to sense - R-wave transition - Intraventricular conduction delay Two new tools: - Syndromes applies a named pattern in one tap: Wellens A and B, de Winter, Brugada 1 and 2, S1Q3T3, pericarditis, early repolarisation, hypothermia, digoxin, electrical alternans, low voltage, P mitrale and P pulmonale, LVH with strain, RVH, hyperkalaemia and hypokalaemia, long QT, poor R-wave progression, left axis deviation - Sequence changes the rhythm partway through the strip, with a shock where you want it The paper prints at 25 or 50 mm/s. Baseline drift, muscle tremor and mains hum each have their own slider. AI Build understands the new patterns and rhythm options. Fixed: - Choosing R-on-T no longer crashes the app - The tool panel keeps one size in landscape, so the ### 1.0 โ€” 2026-09-20 No release notes. ## More apps by Mark Daniel Figueroa - [CardioLens](https://appshunter.io/ios/app/cardiolens/id6761556643) - [ACLSMED Sim](https://appshunter.io/ios/app/aclsmed-sim/id6771604723) - [Prayerful Rosary](https://appshunter.io/ios/app/prayerful-rosary/id6782238801) - [NCLEX Pulse](https://appshunter.io/ios/app/nclex-pulse/id6784326446) - [ACLSMED CPR](https://appshunter.io/ios/app/aclsmed-cpr/id6792341448) All apps by Mark Daniel Figueroa: https://appshunter.io/developer/1890265406 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-22.*