—About
About me
Software engineer by day, building companies on the side — always looking for ways to create something useful.
I'm Gunawan Santoso, a software engineer based in Jakarta, Indonesia. I've spent the past several years working at companies like 
Shopee, 
Gojek, 
Waresix, and 
Sinarmas Group — building frontend systems, shipping products, and learning what it takes to create software that people rely on every day.
Outside of work, I founded 
Micro App Digital, where I create simple Android and iOS apps for everyday use, and co-founded 
Incrementum, a digital solutions company that helps businesses build and grow their online presence.
AI is a natural extension of the workflow — from faster prototyping to better code, it frees up energy for the decisions that actually matter. The craft stays human, the speed just gets multiplied.
Connect with me—Independent apps
73+ mobile apps — designed, coded, and shipped solo on Android and iOS.
PT Micro App Digital is my independent app studio, building focused, privacy-first mobile applications that solve everyday problems with clarity and craft — no bloat, no accounts, and data that stays on your device. Every product is taken end-to-end, from concept and design to code and release.
The classic word search done right — Classic/Large/Extra Large print that reflows the whole puzzle, a highlighter stroke that follows your finger, six themed packs, a 14×14 Big Puzzle & a shared Daily, offline
A small round friend who never dies and never guilts you — three-second feeding, toss & petting, four growth stages, hats and outfits, and a daily gift. No sad meters, works offline, no account
Every grid certified line-solvable by a solver before it ships — one solution, pure logic, never a guess. No hearts or energy, solved pictures bloom into a Gallery, six packs from 5×5 to 20×20, offline
Untangling puzzle with the maths on its side — every board proven clearable and deadlock-free, no hearts or timers, blocked arrows just bounce. Journey, dense Knots & a worldwide Daily Tangle, offline
Countdown widgets in six styles with twelve themes, nothing locked — count down and count up, yearly repeats, calendar-day maths that's never off by one, and an IT'S TODAY flip at zero. Offline
Illustrated somatic routines picked by the moment you're in — Unclench, Come back down, Loosen or Land — with a two-minute Reset one tap away, an unscored body check-in & low-stim mode, offline
Couples questions, party rounds & family game night in one deck — nothing you say is ever stored, and nothing leaves the phone
Ten original film stocks with grain and bloom, on-viewfinder grain & light-leak dials, three date-stamp styles, re-developable negatives — full resolution, no watermark, developed on-device
Water sort where every level is proven solvable before you see it — minimum move count on the board, sealed shareable seeds, Journey/Zen/Daily Sort, colourblind patterns & unlimited undo, no lives or timers
Block puzzle that plays straight — every tray drawn from a published set by a visible seed you can verify, shareable seeds, Classic & Zen modes, streak fever, a worldwide daily board, no energy or lives
Classic Klondike, calm and complete — verified Winnable Deals or honest random shuffles, draw-1/draw-3, Standard/Vegas scoring, daily crown, trophy calendar & unlimited undo, fully offline
Write on a calm serif page or log a day in ten seconds — mood & activity check-ins, On This Day, year in pixels, PIN/fingerprint lock & PDF/Markdown/JSON export, offline
Build a vision board in minutes — your own photos at full resolution, drag/resize/rotate with snap guides, goals with dates & milestones, a 60-second Morning Minute and an Achieved gallery, offline
Time you can see — a full-screen wedge that drains, a gentle heads-up and quiet amber overtime, ~3-second thought capture, step-by-step Flows with live done-by times, low-stim mode, offline
A living orb expands, holds & releases with your breath, with gentle haptics — 4-7-8, box & coherent breathing, Quick Calm, a sleep wind-down & calm-delta from mood check-ins, offline
See where your time goes — app usage, unlocks & notifications, unlimited history, per-app limits with a real block screen, strict mode, focus sessions & a floating live timer
16 Personality Types, Big Five, Enneagram & DISC — one evolving profile with instant results, compatibility checks & shareable cards, free & offline
Private period & cycle tracker — flow, symptoms, mood & fertile window, with honest predictions, PIN lock, doctor-ready PDF & TTC mode, free & offline
Intermittent fasting tracker with live fat-burning/ketosis/autophagy stages, every schedule (16:8, OMAD, 5:2), weight tracking & streaks — fully free
See your whole week at a glance and plan it like a paper planner — capture tasks fast, set recurring schedules & subtasks, organize into lists, with device calendar events alongside. Free & offline
Record in high quality, then read it back as searchable text — on-device transcription with no time limits, tap a word to jump to that moment, edit (trim/split/merge) & background recording. Free & offline
Make your home screen yours — live widget editor with instant preview, curated wallpapers, one-tap icon packs, matching themes & charging animations — free & offline
Catalog everything you own — photos, values, serial numbers & receipts across rooms & properties, with barcode scan, warranty reminders & claim-ready PDF
Track every service, fuel-up, expense, document & reminder for unlimited vehicles — fuel/EV economy, photo records & PDF/CSV export, fully offline
Paint your rotation once — 2-2-3, 4 on 4 off, DuPont, Pitman or your own cycle — and see the whole year, with per-shift wake alarms, pay estimates & a scannable pattern code, offline
Customizable watering & care reminders for every plant — organized by room, with smart schedules, an offline care library & a growth photo journal
Calm, private week-by-week pregnancy tracker with kick counter, contraction timer, weight & symptom logs, appointments, checklists & bump journal
Track feeding, meds, vaccines, weight, vet visits & grooming with a photo journal — unlimited pets, reminders & on-device records
Kind words where you'll see them — a daily affirmation, a practice that ends when you're done, and your own words alongside. Every category included, works offline
The most complete Kraepelin & Pauli psychometric test trainer for CPNS, BUMN & job selection
Track transactions, manage budgets, and monitor multiple wallets in one simple app
Discover the richness of traditional Chinese calendar systems
Monitor screen time, set goals, and build healthier digital habits
Beautiful weather with animated illustrations, hourly forecast, and 10+ home widgets
Intermittent fasting timer & tracker with 17+ plans, schedules, and stats
Understand your cycle through four seasons with daily logging and insights
Simple stopwatch timer with labels, insights, and activity heatmap
Build lasting habits through small, consistent daily actions
Ishihara, Snellen, contrast & astigmatism — the complete offline eye test in 2 minutes
Private, on-device money manager with budgets, goals, debt, assets & net worth
Daily crossword challenges with 4 difficulty levels, hints, themes & stats
Test your internet against Cloudflare's 300+ global servers. Download, upload, ping, jitter — in 15 seconds. 30-day history with trend charts and CSV export
MBTI, Big Five, Enneagram & Love Language tests in one beautiful offline app
Test love compatibility 6 ways — name, zodiac, birthday, fingerprint, photo & quiz
Offline grocery lists, pantry tracker, budget — no account, no cloud
All-in-one productivity with todo list, Pomodoro timer, and timebox planner
Bright LED flashlight with compass, magnifier, SOS beacon, level, and ruler
Test your IQ, train your brain & track your score across 7 cognitive categories
Random spinner wheel, dice, coin, team maker & more decision tools for groups
Beautiful countdown timers for birthdays, trips, holidays & every moment that matters
Weekly meal planner with 300+ recipes, auto grocery lists & hands-free cooking mode — offline
Honest file cleaner with duplicate finder, storage analyzer, recycle bin & full file manager
10 scientific memory tests — digit span, Corsi block, N-back, Simon & more
8 scientific reaction tests — simple, choice, go/no-go, audio, memory & more
Track water intake with one tap. Smart reminders that stop when you reach your daily goal. 7 drink types, beautiful animated water vessel, 12 languages — fully offline
Make flashcards, study with spaced repetition. 4 modes (Flip, Quiz, Match, Type), streaks, achievements, 12 languages — fully offline
Create invoices, estimates, and receipts in 2 minutes. 10 templates, 30+ currencies, 100% offline
Calculate BMI, log weight & track wellness with 16 health calculators — private & offline
Classic 2048 with multiple modes, daily challenges, 8 themes & smooth animations
Effortlessly scan and process QR codes and barcodes instantly
Read, edit, merge, compress, sign & convert PDFs — 100% on-device, no uploads
A beautiful daily journal for writing, memories, photos and mood. Year in Pixels, On This Day flashbacks, streak tracking — 100% offline
Fast offline unit converter — 20 categories and 100+ units including length, weight, currency, BMI and cooking sizes
Beautiful Chinese almanac — daily lunar dates, Tung Shing, zodiac, festivals & auspicious-date finder, fully offline
Forgiving habit tracker with a habit-strength score, consistency grid, goals, routines & a living garden — 100% offline
Offline mind mapping with 6 layout modes, infinite canvas, focus mode, present mode, outline view & 15 templates
Track every book, time every session, save your favorite quotes. Year-in-Books cover grid, reading calendar, genre charts, 15 achievements. 100% offline, 12 languages
Chromatic tuner with one-cent accuracy + tap-tempo metronome. 30+ tunings, all unlocked, fully offline
—IT solutions
Incrementum
A digital solutions company that helps businesses design, build, and grow through technology.
PT Incrementum Digital Solutions is a digital solutions company I co-founded to help businesses with their technology needs — from web development and mobile apps to internal dashboards and e-commerce platforms. We also provide penetration testing and network security assessments to help clients identify vulnerabilities and strengthen their infrastructure before threats become problems.
What drives me.
Build with purpose
Every product should solve a real problem. I focus on utility over complexity — creating tools that genuinely improve how people work and live.
Put users first
Great software starts with understanding the people who use it. Clean interfaces, thoughtful interactions, and accessibility aren't afterthoughts — they're the foundation.
Grow incrementally
Whether it's a personal app or a client project, I believe in shipping early, iterating often, and letting real feedback guide the direction.