HighSerpent
000
Sudoku · Math · Finance · Android

Software
that respects
your space.

Three small Android apps. A sudoku-solving alarm clock, a math card game, and a loan calculator that solves for any unknown. Free, offline, no signup.

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[ §02 ] What we believe

Most apps want a relationship. Ours don't.

01 / 03

One job,
done well.

Each app solves one problem completely. No dashboards, no upsells, no second tab you didn't ask for. Open it, use it, close it.

02 / 03

No attention
tax.

No ads. No streak guilt. No notifications begging for return visits. Made to be useful — not to keep you coming back.

03 / 03

Quiet
by design.

Editorial typography. Restrained palettes. No anxious red badges. Tools that sit beside your day, not in front of it.

Three apps,
each built to
do one thing.

[ §03 / THREE PRODUCTS ]
All free. All offline.
Open them when you need them.
[ 01 / 03 ]

SudokuSense.

Wake up by solving a sudoku.

An alarm clock that asks for a single cell before it stops ringing. Scan the puzzle from a newspaper, type one in, or pick the daily — then practise techniques (Naked Singles, X-Wing, and beyond) in the trainer.

Alarm Sudoku OCR Practice
[ 02 / 03 ]

Cardculus.

Mental math as a card game.

Five-minute brain workouts disguised as a card puzzle. Build expressions from the cards you draw to land exactly on the target. Four difficulty tiers, nine themes, a daily streak — without the "educational software" feel.

Brain training Math Daily streak
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[ 03 / 03 ]

LoanLab.

A loan calculator that solves for any field.

Leave any one of amount, rate, tenure, or EMI blank — LoanLab works out the rest. Compare paying down a loan against an SIP, model prepayments, and export the full amortization schedule.

EMI Amortization Compare
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The best software earns your attention. It doesn't demand it.