Subway3D vs Flips

This app has a 3D representation of five different subway systems: Paris, Moscow, London, Tokyo and New York. The app is a 3D map, showing each subway station's location and the elevation and location of the subway lines in the station and between stations. If you are in the city, the app can determine the nearest subway station, and calculate a route to any other station in the system. The map can be zoomed, and rotated around the x,y or z axis to get a view of the system from any angle.

Flips is a flashcard app that brings back each card right before you're about to forget it. Built on the forgetting curve and spaced repetition (SRS), it works for anything worth memorizing — vocabulary, exam terms, dates, professional jargon, and more. Key Features ・Just-in-time review (SRS) Cards resurface automatically at the best moment to review. Mastered cards space out; shaky ones come back sooner — the shortest path to remembering. ・Simple, fast study sessions Open the app and start right away. Swipe or pick from 4 choices — nothing gets in the way of focus. ・Memory home screen A chart shows what you've learned, what's fading, and what's new at a glance. Today's study count is always clear. ・Streaks to build the habit Your study streak is shown like a calendar, so daily effort visibly adds up. ・Forgetting gauge & levels See each card's "risk level" in your deck list, so you always know what to review first. ・Create decks & import Build a deck in minutes, or import from CSV/TSV. ・Notifications at the right time Get reminded exactly when review will be most effective. ・Text-to-speech (TTS) Hear pronunciation for listening practice or a quick check. (Supported languages depend on your device; more are added over time.) Great for ・Language vocabulary: words, phrases, listening practice — Spanish, French, Japanese, or any language ・School & exams: history dates, science terms, formulas, standardized test prep ・Certifications: professional exams, medical, legal, and IT terminology ・Anything else: whatever you need to memorize How it works (3 steps) 1. Pick a deck or make one (ready-made vocabulary decks, or build your own) 2. Start studying (cards you're about to forget come up first) 3. A little every day (streaks and charts make progress visible) Why you'll remember with Flips ・Science-based: spaced repetition tuned to the forgetting curve optimizes your review timing ・Built for focus: a stripped-down interface, studying in two taps ・Priorities made visible: the forgetting gauge and "due today" count remove the guesswork ・Built for habit: streaks keep you coming back Common ways people use Flips ・Students: vocabulary, historical dates, formulas, test prep ・Working professionals: certification vocabulary, technical terms, on-the-job knowledge ・Language learners: vocabulary across any language you're studying What Flips values ・Simple and fast: built to help you focus purely on remembering ・Visible progress: progress, streaks, and forgetting risk, always in view ・Flexibility: build your own decks or import to fit any subject Start for free, and build a study habit around reviewing right before you forget.