ChemSearch for Android

ChemSearch: Chemistry simplified.
Compound search, structures, offline saves, and practical chemistry tools for Android.

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About

ChemSearch is an Android chemistry app I built to make compound lookup less annoying. Search a compound, check the formula and identifiers, open the 2D or 3D structure, read safety notes, save it for offline use, or jump into calculators when you need a quick result.

It is meant for students, teachers, and quick lab-prep checks. Not a replacement for an SDS or proper lab rules, but handy when you need chemistry data on your phone without bouncing between PubChem, Wikipedia, and separate calculator sites.

Highlights

• Search by compound name, CAS number, formula, or PubChem CID.
• View 2D structures and interactive 3D molecular models.
• Save full compound data for offline use, including structures, identifiers, descriptions, synonyms, safety data, and source metadata.
• Compare several compounds side by side.
• Browse a built-in chemical database with 659 entries across substances, ions, functional groups, and reactions.
• Use chemistry tools for molar mass, pH/pOH, oxidation states, reaction balancing, stoichiometry, dilution, gas laws, isomers, and SMILES lookup.
• Choose PubChem, Wikipedia, Gemini, Groq, OpenAI, OpenRouter, or Mistral for descriptions.
• Use list/grid layouts, tool reordering, pinned recents, formula display modes, light mode, dark mode, AMOLED Mode, compact mode, accessibility options, and multiple color schemes.

Screenshots

Search	Light Mode	3D Viewer

Library / Favorites	Tools	Identifiers

Descriptions	GHS Safety	Molar Mass

Oxidation States	Reaction Balancer	SMILES Viewer

Compound Search

ChemSearch can look up compounds using several common identifiers:

• Name, such as glucose, sodium chloride, or sulfuric acid.
• CAS number.
• Molecular formula.
• PubChem CID.

Autosuggestions can query PubChem while you type, and repeated searches can load faster from the app cache.

The result page focuses on the details people usually need first:

• Compound name and formula.
• CID, CAS number, and molecular weight.
• IUPAC name, InChI, InChIKey, SMILES, and synonyms.
• 2D structure image.
• 3D structure viewer.
• GHS safety information when available.
• Descriptions from the selected source.
• Isomer search from the formula.
• Favorite and offline download actions.

Formula display supports subscripts, charge superscripts, wrapping for large formulas, and two ordering styles:

• Conventional: familiar ordering for common compounds, such as NaCl, H2SO4, and NH4+.
• Hill: PubChem-style Hill ordering, such as ClNa or H4N+ when that is the source formula.

Structures

ChemSearch loads structure data from PubChem when it is available.

• 2D structure images are shown directly in the compound page.
• 3D SDF models open in the built-in viewer.
• The default structure tab can be set to 2D, 3D, or the last used tab.
• If PubChem has no 3D model, ChemSearch can try fallback structure loading from identifiers such as SMILES, InChI, and InChIKey.
• Generated or fallback structures are labeled so the source is clear.
• Structure pills include visible outlines in light, dark, and AMOLED themes.

Some atoms, metal compounds, ionic solids, and crystal-like materials do not have a useful standalone 3D molecule. In those cases, ChemSearch explains the missing model or labels the fallback as an estimate instead of presenting it as a confirmed crystal structure.

Descriptions

Descriptions can come from:

• PubChem.
• Wikipedia.
• A configured AI provider.

AI descriptions are optional. Supported providers are Google Gemini, Groq Cloud, OpenAI, OpenRouter, and Mistral AI. ChemSearch can refresh provider model lists and lets you choose a model per provider.

When AI is enabled, ChemSearch uses available compound details such as formula, identifiers, safety data, and source context to keep the generated text grounded. API keys are stored locally with Android Keystore.

Long descriptions can be expanded and collapsed, including inside the compound comparison tool.

Library

The Library screen groups saved and offline content into three areas:

• Favorites: saved compounds for quick access.
• Downloads: offline compound copies.
• Chemical Database: built-in reference data for substances, ions, functional groups, and reactions.

Library supports list and grid layouts. The Chemical Database card keeps the grid layout clean, while the list layout can show database counts from an info button beside the description.

The bundled Chemical Database includes:

• Substances: 331.
• Ions: 108.
• Functional groups: 71.
• Reactions: 149.

Offline downloads save more than a cached result. A downloaded compound can include:

• Basic compound details.
• 2D structure image.
• 3D structure data when available.
• Identifiers.
• Descriptions.
• Synonyms.
• GHS safety information.
• Source metadata.

Offline download quality can be set to Basic, Structures, or Complete depending on how much data you want to save.

Downloads are stored in the local app database and can show saved asset chips such as 2D, 3D, safety, synonyms, descriptions, and identifiers. Older offline copies can be marked stale so you know when a refresh may be useful.

The offline save button shows download progress while the compound data is being saved.

Recent Searches

The Recent screen keeps search history organized by time.

• Pin important searches.
• Sort by newest or oldest from the filter menu.
• Remove single entries.
• Clear all recent searches.

Pinned entries use a pin icon so they are easier to understand at a glance.

Tools

ChemSearch includes practical tools for common chemistry work:

• Molar Mass Calculator: parse a formula and calculate molar mass.
• Oxidation State Finder: estimate oxidation states for compounds, including oxyhalogens, peroxides, superoxides, ozonides, hydrides, and mixed-valence cases.
• pH / pOH Calculator: convert between pH, pOH, hydrogen ion concentration, and hydroxide ion concentration.
• Reaction Balancer: balance chemical equations.
• Isomer Finder: search isomers from a formula and open a result in the main compound screen.
• Limiting Reagent: find limiting reagent, mole ratios, and theoretical yield.
• Percent Yield: compare actual yield against theoretical yield.
• Reaction Scaling: scale reactants for a target product amount.
• Dilution Calculator: calculate concentration and volume changes.
• Ideal Gas Law: work with pressure, volume, amount, and temperature.
• SMILES Visualizer: open structure data from SMILES input.
• Custom 3D Molecule Viewer: load local .sdf or .mol files.
• Compare Compounds: compare formulas, descriptions, identifiers, atom counts, bond counts, molecular weight, and other properties across several compounds.

The Tools page supports search, categories, list/grid layouts, compact mode, drag-style reordering, and a reset action for returning tools to the default order.

Display And Settings

ChemSearch includes display settings for different phones and reading styles:

• Light and dark theme.
• AMOLED Mode for true-black backgrounds in dark mode.
• Color schemes.
• Compact mode.
• Reduce motion.
• High contrast outlines.
• Welcome screen reset for checking onboarding again.
• Autosuggestions.
• Default description source.
• Default structure view.
• Formula display style: Conventional or Hill.
• AI provider keys and model selection.
• Offline download quality.
• Cache location and cache clearing.
• Cache size limit: 10 MB, 50 MB, 100 MB, or unlimited.
• Cache auto-clear schedule: daily, weekly, monthly, or manual.
• Settings import and export.
• Internal app update download with progress in Settings.
• Update notifications.
• Update install prompt after the APK finishes downloading.

Developer Options

Developer options include checks for the app's main data paths:

• PubChem lookup.
• PubChem structures.
• PubChem safety data.
• Wikipedia descriptions.
• NCI/CADD fallback structures.
• GitHub release checks.
• Configured AI providers.

Developer options also include masked preference inspection, debug logging, notification testing, welcome-screen reset, cache and storage summaries, and legacy preference cleanup. Tap the build number five times in the About card to unlock these options.

These checks are useful when a data source changes, a network request fails, or a provider key needs testing.

Built With

• Kotlin
• Jetpack Compose
• Material 3
• AndroidX Navigation Compose
• AndroidX Lifecycle
• Phosphor Icons
• AndroidX Room
• AndroidX DataStore
• AndroidX WorkManager
• Retrofit
• OkHttp
• Gson
• Coil
• Kotlin Coroutines

Data Sources

• PubChem PUG REST for lookup, properties, synonyms, descriptions, images, isomers, and SDF files.
• PubChem PUG View for GHS safety data.
• PubChem autocomplete for search suggestions.
• Wikipedia REST API for general summaries.
• NCI/CADD Chemical Identifier Resolver for fallback SDF models.
• GitHub Releases for app update checks.
• Local JSON files in app/src/main/assets/chemical_database/ for offline reference data.
• IUPAC, LibreTexts, PubChem, and general chemistry references are used as labels or source links inside the local database where available.
• Optional AI provider APIs for generated descriptions: Gemini, Groq, OpenAI, OpenRouter, and Mistral.

Safety data is shown as reference information only. Always follow the official SDS, lab rules, and local safety requirements for real handling decisions.

Accuracy And Limits

ChemSearch is a study and reference tool, not a substitute for lab safety rules, an official SDS, or a chemistry instructor.

• PubChem and Wikipedia results depend on the source data that is available for a compound.
• AI descriptions can be useful, but they should be checked against source data for serious work.
• Fallback 3D structures are estimates when PubChem does not provide a usable 3D model.
• Ionic, metallic, and crystal structures may not be represented by a single molecular 3D model.
• The oxidation state and formula tools cover many common study cases, but unusual coordination compounds and edge cases may need manual checking.

Project Structure

.
|-- app/
|   `-- src/main/
|       |-- assets/chemical_database/
|       |-- java/com/furthersecrets/chemsearch/
|       `-- res/
|-- app/src/test/
|-- .github/
|-- gradle/
|   `-- libs.versions.toml
|-- screenshots/
|-- keystore.properties.example
|-- local.properties.example
|-- build.gradle.kts
|-- settings.gradle.kts
`-- README.md

Useful areas:

• app/src/main/java/com/furthersecrets/chemsearch/ contains the Android app code.
• app/src/main/assets/chemical_database/ contains local reference JSON files.
• app/src/main/res/ contains icons, images, and Android resources.
• app/src/test/ contains unit tests for chemistry parsing, calculators, settings behavior, and UI helper logic.
• .github/ contains GitHub project files when present.
• screenshots/ contains README screenshots.

Download

Download the latest APK from GitHub Releases.

Build From Source

Requirements:

• Android Studio
• JDK 17+
• Android SDK API 36

Clone the repo:

git clone https://github.com/FurtherSecrets24680/chemsearch-android
cd chemsearch-android

Build a debug APK on macOS or Linux:

./gradlew assembleDebug

Build a debug APK on Windows:

.\gradlew.bat assembleDebug

The debug APK is generated at:

app/build/outputs/apk/debug/app-debug.apk

Signed Release Builds

For signed release builds, copy keystore.properties.example to keystore.properties and keep the keystore in the project-relative path shown in the example file.

The local signing files are ignored by Git:

local.properties
keystore.properties
keystores/
*.jks
*.keystore

Build the release APK:

.\gradlew.bat assembleRelease

The release APK is generated at:

app/build/outputs/apk/release/app-release.apk

Windows And macOS Notes

The project is meant to build on both Windows and macOS.

• Use gradlew.bat on Windows.
• Use ./gradlew on macOS and Linux.
• Keep Android SDK paths in local.properties, not in Git.
• Keep signing secrets in keystore.properties, not in Git.
• Keep the keystore path project-relative so both operating systems can resolve it.
• Avoid committing generated build folders.

Documentation

The full feature guide belongs in the GitHub Wiki. It covers search, Library, downloads, tools, AI descriptions, signing, cross-platform setup, and developer notes.

Privacy

• No analytics.
• No tracking.
• No app-owned server.
• Compound data is fetched directly from the selected data source.
• AI requests go directly to the selected AI provider.
• API keys are encrypted locally with Android Keystore.
• Settings export can include AI API keys in the JSON backup if keys are saved. Keep exported settings files private.
• Search history, favorites, downloads, settings, and cache data stay on the device.

License

MIT License. See LICENSE for details.

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