Engineering Systems Toolkit

This app is the definitive visual reference for working engineers, technicians, students, and inspectors. Browse 477 professional-quality diagrams spanning 8 major engineering disciplines — all offline, all in one app.
WHAT IS INSIDE
477 illustrations organized into 8 engineering categories:

Electrical Systems — power distribution, panel wiring, conduit layouts, load centers
Fire Alarm Systems — initiating devices, notification appliances, control panels, wiring
HVAC Systems — air handling, duct networks, chilled water, refrigerant circuits
BIM and Construction — floor plans, riser diagrams, coordination views, LOD references
Enterprise IT — network topology, structured cabling, data center layout, TIA-942
PLC and Automation — ladder logic, I/O modules, PLC panels, field instrumentation
SCADA and Controls — RTU diagrams, HMI screens, Modbus/DNP3 architecture, control loops
RF and Radio Systems — antenna configurations, path diagrams, repeater systems, link diagrams

GLOBAL SEARCH
Search all 477 diagrams instantly by name across every category. One-tap category filter chips let you narrow results to a single engineering discipline in seconds.
DIAGRAM OF THE DAY
A fresh featured diagram appears on the home screen every day — automatically curated from all 8 disciplines. A new reference point every time you open the app.
SHARE ANY DIAGRAM
Send any illustration directly to colleagues, students, or inspection reports using the iOS Share Sheet — available from every diagram in the gallery.
ENGINEERING CALCULATORS
Each category includes a dedicated field calculator:

Voltage Drop — NEC K-factor conductor sizing with pass/fail at 3% threshold
Battery Standby — NFPA 72 battery Ah sizing for fire alarm panels
HVAC — CFM airflow, cooling load in BTU/h and tons, duct sizing at target FPM
BIM Space — multi-room gross/net area, GFA, and volume in imperial or metric
IT Network — PoE budget (802.3af/at/bt) and IPv4 subnet calculator with CIDR
PLC I/O — module count, chassis sizing, and scan time estimation
RF Link Budget — FSPL, path loss, link margin with fading environment presets
SCADA Timing — Modbus RTU frame timing, T3.5 gap, and DNP3 poll cycle load

STANDARDS REFERENCE
Built-in searchable reference covering NFPA 72, NEC, ASHRAE, ISO 19650, IEC 61131-3, IEC 62443, TIA-942, and ITU/FCC standards — filtered by engineering domain.
KEY FEATURES

Swipeable full-screen gallery — page through every diagram in a category
Pinch-to-zoom — inspect fine detail on any illustration
Favorites — star and collect your most-used diagrams
Works fully offline — no internet connection required
iPhone and iPad — optimized for all screen sizes and orientations

Whether you are reviewing a design, studying for a certification, or troubleshooting a system in the field, this app puts 477 reference diagrams and professional engineering tools in your pocket.