28+ Best Apps Like SI for iPhone (2026)

#1

iRhino 3D by Robert McNeel & Associates

3D Viewer & Scanner

Editor's Choice

📊 Productivity

4.6😐(80 ratings)

Free

View and present 3D models from Rhino 3D on your iPhone or iPad. Navigate models with intuitive touch gestures, load files from various sources, and visualize them in augmented reality. Includes a markup tool for annotations.

What We Love

👍 Smooth and intuitive 3D model manipulation
🚀 Fast performance with complex models
📱 Great for client presentations and demos
💼 Useful for on-the-go model viewing
🔄 Good Dropbox integration
📊 Layer control functionality
✨ Clean and polished user interface
🎯 Effective communication tool for design teams
📸 Room scanning and markup capabilities
⚡ Responsive touch controls

Room to Improve

🐛 Frequent crashes on large files
❌ Limited to viewer functionality only
🚫 No native editing capabilities
📉 Poor LiDAR measurement accuracy
🔌 No iCloud Drive support
🎨 No texture or material rendering
📁 Limited file storage integration options
⚠️ Crashes on iPad Pro object scan mode
🔍 Difficult to select specific objects
💾 Cannot save progress on interrupted scans

#2

Electrical Calculations by Egal Net di Ettore Gallina

Cable sizing & capacity

Strong Contender

📊 Productivity

4.6(126 ratings)

FreeAdsIn-App Purchases

This app provides a comprehensive suite of electrical calculations for professionals. It supports various international standards and offers detailed reports in PDF format. The tool covers wiring, power, motor, and electronic calculations, along with extensive conversion tables and resources.

#3

Airmail for Gmail Outlook Mail by Bloop S.R.L.

Your Mail With You

Worth Considering

📊 Productivity

4.2😞(4.1K ratings)

FreeIn-App Purchases

Airmail for Gmail Outlook Mail screenshot 1

Airmail for Gmail Outlook Mail screenshot 2

Airmail for Gmail Outlook Mail screenshot 3

Airmail for Gmail Outlook Mail screenshot 4

This powerful mail client offers a streamlined inbox experience with extensive customization options. It supports multiple email accounts and integrates seamlessly with other apps and services for enhanced productivity. Enjoy features like snoozing, interactive notifications, and iCloud sync for a unified workflow across devices.