JWT Decoder
v1.0.0
Decode, inspect and actually verify JSON Web Tokens — entirely on the device, with no token ever leaving the phone.
The hard part: offline signature verification across 13 algorithms
(HS, RS, PS and ES families). The crypto is validated against test vectors generated
with OpenSSL rather than against itself — which is how the PSS salt-length
mismatch that broke six tests was found instead of shipped.
313 tests+35 on-device
10 localesFlutterDart crypto
not yet released
JSON Formatter
v1.0.0
Format, validate and explore JSON — without silently rewriting the document you pasted in.
The hard part: it does not use json.decode. Dart's built-in parser
changes data: 1e5 becomes 100000.0, 1.50 becomes
1.5, huge integers lose digits and duplicate keys vanish. So this ships a
hand-written recursive-descent scanner that carries every number as literal text,
keeps duplicate keys and reports them, and returns error codes with line and
column — because the messages exist in ten languages.
266 tests10 locales
Custom parserFlutter
Hash Generator
v1.3.0
Digests for text and for files, with a searchable history you can undo.
The hard part: keeping a pure, dependency-free HashEngine testable
while the app around it grew a file picker, an undoable history, a GDPR consent flow
and push topics — a 1,034-line main.dart split into 33 files without
changing a single digest.
154 tests6 locales
UMP consentFCM
Qibla Compass
v1.0.0
Qibla direction, prayer times, manual location and a map — accurate without a network connection.
The hard part: no Flutter compass plugin exposes the two values this app is
built on, so it ships its own HeadingPlugin in Kotlin and Swift: Android's
GeomagneticField declination (true north with no bundled magnetic model and
no network) and the raw magnetometer accuracy bucket, so the app can tell you when to
recalibrate instead of quietly pointing the wrong way.
121 testsKotlin
SwiftSensorsOffline
not yet released
Flip Text
v1.0.0
Upside-down, mirrored and scrambled Unicode text in fifteen styles.
The hard part: Unicode, not UI. Three near-duplicate flip tables disagreed on
15 of 94 shared entries; 280 of 1,158 mirror entries were unreachable dead code
because astral characters are surrogate pairs; and reversal was tearing emoji in half.
Rebuilt as two correct tables plus grapheme-aware reversal.
105 tests15 locales
UnicodeGraphemes
TV Size Calculator
v1.1.0
Screen size against viewing distance — metric and imperial, viewing angle, real screen dimensions and a scaled room diagram.
The hard part: the pass that mattered was done on a phone, not in CI. A green
test suite still shipped a clipped tab bar, a locale pinned at install time and a
counter truncated to one line. Android's font scaling is non-linear above 100%, and no
widget test notices.
186 tests15 locales
Metric + imperiala11y
Shade Shift
v1.0.0
Spot the one tile whose shade is different, against the clock, with a daily challenge.
The hard part: difficulty is a target CIE76 ΔE per level rather than
an RGB step, found by bisection to within ±0.4 ΔE — so level 40 is
perceptually harder than level 20 on every panel. The daily challenge needs no server:
the date seeds a PRNG that is pinned in-app so it can never drift between releases.
94 testsColour science
Deterministic PRNGOffline
not yet released
Text Repeater
v1.3.0
Repeat text by count or by target length, with custom separators, escape sequences and file export.
The hard part: staying responsive at scale. Anything over 50,000 characters is
generated on a background isolate, so the UI never blocks — and the enum is
AmountMode, not RepeatMode, because Flutter's material library
already exports that name and the ambiguity is silent.
56 tests8 locales
IsolatesSAF export
Quick Chat WA
v1.3.0
Open a WhatsApp chat with any number without saving it to your contacts first.
The hard part: privacy and RTL. An earlier release was logging full phone
numbers and message lengths to analytics; that came out, and the events now carry
outcomes only. Arabic exposed a second class of bug — bidi reordering renders
+971 50 123 4567 back-to-front unless the number is isolated.
45 tests8 locales
RTL / bidiPrivacy fix