The latest articles on DEV Community by Zykrave (@zykrave). https://dev.to/zykrave https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F4140464%2F8795ccd7-6b8a-4869-b498-ae0f853c6c2a.jpg https://dev.to/zykrave en Zykrave Thu, 24 Sep 2026 05:58:49 +0000 https://dev.to/zykrave/i-built-a-47-tool-offline-android-app-with-kotlin-and-jetpack-compose-4pap https://dev.to/zykrave/i-built-a-47-tool-offline-android-app-with-kotlin-and-jetpack-compose-4pap <h2> What is ToolixHub? </h2> <ul> <li> <strong>ToolixHub</strong> is an <em>everyday utility Swiss Knife</em> for Android</li> <li> <strong>47 tools</strong> in one app, across <strong>9 categories</strong> </li> <li> <strong>100% offline</strong>: no accounts, no ads, no network calls</li> <li> <strong>Open source</strong>: <a href="https://github.com/Zykrave/ToolixHub" rel="noopener noreferrer">github.com/Zykrave/ToolixHub</a> </li> </ul> <p>[SCREENSHOT 1: <br> <a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Fen513mvm9cxik8ptwlrm.jpg" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Fen513mvm9cxik8ptwlrm.jpg" alt=" " width="800" height="1778"></a>]</p> <h2> What's inside </h2> <ul> <li> <strong>Calculators</strong>: standard calculator with history</li> <li> <strong>Text</strong>: word &amp; character counter, find &amp; replace, duplicate remover</li> <li> <strong>Image</strong>: resizer, Base64 converter</li> <li> <strong>Random</strong>: name generator, decision maker, number generator</li> <li> <strong>Finance</strong>: loan EMI calculator</li> <li> <strong>Color</strong>, <strong>Measurement</strong>, <strong>Timers</strong> (stopwatch with laps) and <strong>QR &amp; Utility</strong> (QR generator, hash &amp; checksum generator, system info dashboard)</li> <li> <strong>Favorites</strong> and a <strong>Recently Used</strong> row for quick access</li> </ul> <p>[SCREENSHOT 2: <br> <a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Fmiahb9adk5l4t3jgtukh.jpg" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Fmiahb9adk5l4t3jgtukh.jpg" alt=" " width="800" height="1778"></a>]</p> <h2> How I built it </h2> <ul> <li>I used AI only to get the <strong>base and the concept</strong> </li> <li>Everything after that, I built myself with help of ai in <strong>Android Studio</strong>: <ul> <li>Renamed and rebranded the app</li> <li>Designed a custom adaptive icon and splash screen</li> <li>Built a shared design system: category accent colors, reusable components, consistent cards</li> <li>Cleaned up the repo (<code>.gitignore</code>, structure, signing config)</li> <li>Tested every change on a real device</li> </ul> </li> </ul> <p>[SCREENSHOT 3: <br> <a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Fn42j0w9veojoritpronv.jpg" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Fn42j0w9veojoritpronv.jpg" alt=" " width="800" height="1778"></a>]</p> <h2> The tech stack </h2> <ul> <li> <strong>Kotlin</strong> + <strong>Jetpack Compose</strong> + <strong>Material 3</strong> </li> <li> <strong>Navigation Compose</strong> for screens</li> <li> <strong>DataStore</strong> for local preferences (favorites, recents)</li> <li> <strong>ZXing</strong> for QR and barcode handling</li> <li> <strong>Coroutines</strong> for async work</li> <li> <code>minSdk 24</code>, <code>targetSdk 36</code> </li> </ul> <h2> Rules I set for myself </h2> <ul> <li> <strong>No network dependencies, ever.</strong> It must work in airplane mode.</li> <li> <strong>No local database.</strong> DataStore is enough for this app.</li> <li> <strong>No <code>Modifier.blur()</code> or <code>RenderEffect</code>.</strong> They need API 31+, and I support API 24. <ul> <li>For depth, I used gradients and layered shadows instead.</li> </ul> </li> <li> <strong>One small change at a time</strong>, tested on a real device before moving on.</li> </ul> <h2> Lessons learned </h2> <ul> <li> <strong>AI gets you a base fast, but polish is still on you.</strong> The design system, consistency and constraints came from me.</li> <li> <strong>A starting base is not a finished product.</strong> The design system, consistency and constraints all came from hands-on work in Android Studio.</li> <li> <strong><code>Modifier.shadow()</code> on a <code>Card</code> can get clipped</strong> by the card's own shape. Wrapping the Card in a Box that carries the shadow fixed it.</li> <li> <strong>Test shared components on several screens.</strong> A change to one card affects 90+ call sites.</li> <li> <strong>When something doesn't render, try an extreme test value first.</strong> It tells you whether the effect is "too subtle" or "not working at all."</li> </ul> <h2> What's next </h2> <ul> <li>A <strong>scientific mode</strong> for the calculator</li> <li> <strong>Save/download</strong> options for tools that generate content</li> <li>Smoother screen transitions</li> <li>A more distinctive UI redesign</li> </ul> <h2> Try it </h2> <ul> <li> <strong>Download the APK:</strong> [<a href="https://github.com/Zykrave/ToolixHub/releases/tag/v1.2.0" rel="noopener noreferrer">https://github.com/Zykrave/ToolixHub/releases/tag/v1.2.0</a>]</li> <li> <strong>Source code:</strong> <a href="https://github.com/Zykrave/ToolixHub" rel="noopener noreferrer">github.com/Zykrave/ToolixHub</a> </li> <li>Feedback and issues are welcome. If you'd like a tool added, drop it in the comments.</li> </ul> <p><em>Built by <a href="https://github.com/Zykrave" rel="noopener noreferrer">Zykrave</a></em></p> android kotlin opensource