ChemSearch is an open-source chemistry reference and utility app for Android. Search compounds, inspect structures, browse offline references, and use practical chemistry tools all in one place. SEARCH Search PubChem by name, CAS number, formula, CID, or structure. Includes autosuggestions, spelling matches, caching, and specific error diagnostics. Advanced Search filters by elements (included/excluded), molecular weight, charge, 3D data, GHS hazards, and name text. Result pages provide identifiers, structures, safety data, synonyms, and summaries with tap-to-copy actions. Expanding a result also reveals the compound's published spectra (NMR, IR, mass, UV, and Raman) grouped by technique. STRUCTURE & ISOMER SEARCH • Structure Search: Draw molecules with atoms, bonds, charges, and templates. Search PubChem for exact, substructure, superstructure, or similarity matches. Import/export SMILES, InChI, and MOL files. • Isomer Search: Search compounds by molecular formula. View molar mass, atom counts, and degrees of unsaturation. Sort by relevance or name. PERIODIC TABLE Browse all 118 elements with category filters, shell diagrams, physical properties, and spectra. Interactive heatmaps display trends for electronegativity, atomic radius, ionization energy, density, melting point, and boiling point (in K, °C, or °F) with top-five rankings. CHEMICAL DATABASE Offline database with 1500+ substances, 200+ ions, 120+ functional groups, and 300+ reactions. Covers acids, salts, oxides, ores, polymers, amino acids, vitamins, alkaloids, drugs, esters, organometallics, and silicates. Search by name, alias, or formula. CHEMISTRY TOOLS Includes 15 tools for calculations and reference: • Molar Mass Calculator • Empirical Formula Finder • Oxidation State Finder • pH / pOH Calculator • Reaction Balancer • Precipitate Predictor • Reaction Predictor • Limiting Reagent • Percent Yield • Reaction Scaling • Dilution Calculator • Ideal Gas Law • SMILES Visualizer • 3D Molecule Viewer • C