Five cognitive workouts and a cosmic jigsaw puzzle, combined into one free Android app. Train your memory, sharpen your focus, and solve puzzles — no login, no subscription, no internet required.
Free to Download · Ad-SupportedNeuroNova is a brain-training and puzzle app built by Mugavari, the same one-person studio behind RedShield SOS. It packages five short cognitive workouts — each targeting a different mental skill — alongside ZigJaw, a fully original jigsaw puzzle game with adjustable grid sizes and jigsaw-shaped tile edges.
The app is designed for short sessions: five minutes while waiting, ten minutes before bed, or a quick run during a break. Every mode has a clear goal, an explanation before you start, and a score at the end so you know how you did. There are no daily streaks nagging you, no energy bars to refill, no social feeds to scroll. You pick a game, you play it, and you leave.
NeuroNova is built natively in Kotlin with Jetpack Compose. It runs smoothly on low-end Android devices and stores all data on-device — nothing leaves your phone.
Each mode in NeuroNova targets a distinct cognitive function. You can play them individually or run through all five in a single session. Session length is your choice — pick how many rounds you want before you start. Your score and accuracy are shown at the end of every session so you can track improvement over time.
Spot the pattern. Hold it in mind. Reproduce it.
Watch the sequence. Repeat it. It grows each round.
Fast mental arithmetic. Pick the right answer before time runs out.
Mind trick: tap the ink colour, not the word.
Same shape rotated, or an entirely different shape?
ZigJaw is NeuroNova's second major mode: a fully original jigsaw puzzle game built entirely in Jetpack Compose. Unlike the brain workouts, ZigJaw is unhurried — it is a calm spatial puzzle you work through at your own pace.
Rearrange scrambled puzzle tiles to recreate the original image. Choose your difficulty, use the hint if you are stuck, and preview the finished image at any time.
Grid sizes available
Piece shapes
Choose between flat square tiles or ZigLock pieces with genuine interlocking jigsaw edges — tabs and blanks drawn with Compose's GenericShape API, giving a real puzzle feel on a touchscreen.
How to play
Cognitive training apps get a bad reputation because most of them overpromise and underdeliver. NeuroNova does not claim to make you smarter. What it does is give you a structured, repeatable way to exercise specific mental skills — working memory, sustained attention, processing speed, spatial reasoning — in short sessions that fit into a real day.
The five modes in NeuroNova each map to a well-studied cognitive construct:
Memory Grid directly exercises the ability to hold a pattern in mind and reproduce it — the core definition of working memory capacity.
Color Clash is a digital version of the Stroop test, a standard measure of selective attention and the ability to ignore competing information.
Pattern Pulse mirrors the structure of the Corsi block test — a forward span task used in neuropsychological assessments since the 1970s.
Quick Math exercises arithmetic fluency under time pressure — a measure that correlates with general mental processing speed in cognitive research.
Rotate Match trains mental rotation — the same skill measured by Shepard–Metzler tasks, and a strong predictor of performance in STEM subjects.
ZigJaw builds a different skill — deliberate spatial reasoning and image decomposition, without a timer, rewarding careful observation over speed.
| Mode | Skill trained | Timer? | Difficulty |
|---|---|---|---|
| 🧩 Memory Grid | Working memory | 2-sec memorise window | Increases each round |
| 🔵 Pattern Pulse | Sequential memory | Watch phase only | Sequence grows by 1 each round |
| ➕ Quick Math | Processing speed | Per-question countdown | Fixed — speed is the challenge |
| 🎨 Color Clash | Selective attention | Per-question countdown | Fixed — interference is the challenge |
| 🔄 Rotate Match | Spatial reasoning | Per-question countdown | Shapes increase in complexity |
| 🧩 ZigJaw | Visual-spatial puzzle | No timer — self-paced | Choose 3×3 to 6×6 |
NeuroNova is developed and maintained by Azhagiri, a solo Android developer based in Tirupattur district, Tamil Nadu, India. It is published under the Mugavari brand — the same studio that builds RedShield SOS, a personal safety alert app, and ChromeBlitz, a neon reaction game.
NeuroNova started as an experiment — a place to explore Jetpack Compose's composable canvas capabilities, custom shape APIs, and session-based state management. It grew into a complete app with two distinct game systems: the five timed brain workouts, and ZigJaw's relaxed puzzle engine. Both systems share a single hub screen and a consistent design language.
The app is free to download and ad-supported — banner ads help keep development going. There are no subscriptions and no premium modes locked behind a paywall. Every game mode, including ZigJaw, is available from the moment you install. It is built on the same independent-developer philosophy that runs through everything Mugavari makes: the full app is the version anyone can download.
Mugavari is registered under India's MSME Udyam scheme (UDYAM-TN-36-0058447). Learn more on the About page.
No. All game logic runs on-device. You do not need Wi-Fi or mobile data to play any mode. Scores are stored locally on your phone — there is no cloud sync or online leaderboard.
NeuroNova is free to download. It is ad-supported — banner ads are shown in the app. There are no in-app purchases and no premium tier. All five brain workout modes and ZigJaw are fully available without paying anything.
NeuroNova targets modern Android and runs well on devices from Android 8.0 (Oreo) onwards. It is built with Jetpack Compose, so it requires a reasonably recent version of Google Play Services on older devices.
Yes. Before starting any brain workout, you select a session length — how many rounds you want to complete. This lets you fit a session into whatever time you have, whether that is three minutes or fifteen.
ZigJaw difficulty is set by the grid size you choose before starting. A 3×3 grid gives you 9 tiles — approachable and quick. A 6×6 grid gives you 36 tiles — significantly more challenging. You also choose whether to use flat square tiles or ZigLock jigsaw pieces. ZigLock pieces add a visual layer of complexity because the interlocking shapes require spatial matching, not just position matching.
Yes. Each game mode shows a step-by-step how-to-play screen before your first session, explaining the rules and scoring. ZigJaw has its own dedicated setup screen with full instructions.