By a solo Android developer
Small, fast tools for
Android & Jetpack Compose.
No sign-up, no clutter. Convert colors, size up your builds, and sort out Gradle versions — the everyday chores, done in one tap. Built and battle-tested while shipping real apps to Google Play.
Jetpack Compose Color Converter
HEX to Color(0xFF…), plus XML, RGBA, HSL, an alpha slider and a WCAG contrast check.
dp / sp / px Converter
Convert dp, sp and px across every density bucket (mdpi–xxxhdpi), with a font-scale option for text.
AdMob eCPM & Revenue Calculator
Project daily, monthly and yearly ad revenue from DAU, impressions and eCPM — and calculate eCPM from earnings.
API Level ↔ Version ↔ Codename
Search any Android API level, version, codename or VERSION_CODES constant. Current to API 37.
JSON Formatter & Validator
Pretty-print, validate and minify JSON with clear error messages. Runs entirely in your browser.
JWT Decoder
Read a token's header and payload, with expiry and issued-at shown as dates. Decodes locally — no upload.
Unix Timestamp Converter
Convert epoch ↔ date in local time and UTC, seconds or milliseconds, with a live current timestamp.
minSdk vs targetSdk vs compileSdk
What each SDK setting actually controls, how they relate, and how to choose sensible values.
Fix missing translations in an AAB
Why language splitting shows English instead of your translations — and the one-line fix.
AGP · Kotlin · Compose Version Check
Find a compatible set of Gradle plugin, Kotlin and Compose compiler versions.
Why these tools exist
Every one of these started as a chore I hit while building and publishing my own Android apps — pasting a hex into a Color(0xFF…) literal, checking whether a color passed contrast, working out which Kotlin version a Compose compiler wants. Instead of searching each time, I turned them into small single-purpose pages that load fast, run entirely in your browser, and never ask you to sign in. New tools land here as I build them.