Flashing Light: Morse Trainer

Osprey Applications LLC

In-app purchases

About this app

Flashing Light: Morse Trainer prepares mariners for U.S. Coast Guard (USCG) flashing-light competency. License candidates, maritime academy cadets, and renewing officers practice receiving, transmitting, and decoding visual Morse code at exam-realistic speeds (4–8 WPM).

DISCLAIMER: This is an independent study aid. It is not affiliated with, endorsed by, or sponsored by the U.S. Coast Guard or any other government entity, and it does not represent or provide services on behalf of any government agency. Official sources are linked below.

Built for real exam preparation, not gamified streaks — a single high-contrast signal lamp on a dark, low-glare screen, scored by real accuracy:

• Receive drills — read the on-screen signal lamp: single characters, code groups, distress + single-letter signals.
• Transmit drills — press-and-hold lamp key with per-pulse timing feedback and a light haptic on each key-down.
• ICS code-group drills — decode + meaning multiple-choice against the International Code of Signals (PUB 102) reference.
• Mock Exam — spec-default sequence combining all three skills.
• Learn screen — A–Z + 0–9 Morse code reference grid with tap-to-flash preview and spaced-repetition tracks.
• Readiness estimator — per-axis accuracy + replay-dependence against U.S. Coast Guard target thresholds.
• Beginner mode — wider classifier thresholds and a visible threshold caption for first-time users; flip off for exam-strict practice.
• JSON progress export — full session history, mastery stats, and settings via the Android share sheet (no cloud upload).

WHO IT'S FOR
USCG deck-license candidates, merchant mariner credential (MMC) applicants, and maritime academy cadets preparing for the flashing-light visual signaling test. CW operators and Morse code hobbyists who want disciplined signal-lamp practice — clean dots, dashes, and timing — will feel at home too.

Photosensitivity-aware: a first-launch warning explains the flashing content, the in-app Reduce Motion mode replaces the lamp animation with a static indicator, and Symbolic-Only mode renders patterns as text with no flashes at all. TalkBack labels are provided throughout.

No accounts, no ads, no analytics. All practice content ships bundled — learn Morse code completely offline.

One-time purchase unlocks Transmit, ICS, Mock Exam, all WPM speeds, and progress export. Receive at 4 WPM and the Learn Morse code reference grid are free to explore before you buy.

OFFICIAL SOURCES
The government information referenced in this app comes from these official sources:
• U.S. Coast Guard National Maritime Center — mariner credentialing and examinations: https://www.dco.uscg.mil/nmc/
• Merchant mariner credential and examination requirements (46 CFR Part 11): https://www.ecfr.gov/current/title-46/chapter-I/subchapter-B/part-11
• International Code of Signals (PUB 102), National Geospatial-Intelligence Agency: https://msi.nga.mil/Publications/ICOS

Designed for Android phones. Works completely offline.

What’s new

First release of Flashing Light: Morse Trainer for Android.

Practice visual Morse code for USCG flashing-light competency — fully offline:
• Learn track with spaced-repetition review
• Receive drills: read the on-screen signal lamp
• Transmit drills: key dots and dashes on the lamp
• ICS / PUB 102 code-group practice
• Timed Mock Exam
• Progress, review, and JSON export

Includes a photosensitivity safeguard with reduce-motion and symbolic-only modes.