Observer Pro vs Mohr's CSA

Observer Pro is an indispensable app for advanced astronomy observing and astrophotography planning. No more guessing when that galaxy emerges from behind that tree. No more estimating how many hours you'll be able to image an object. Observer Pro gives every astronomer the info they need to make the most of their observing right at their fingertips! What astronomers are saying: "Every astronomer with an iPhone should own this app!" - Astronomy Technology Today magazine "Observer Pro is the most impressive astronomy app that I have tried out. I enthusiastically commend it to you!" - Tom Mote, Professor Emeritus, Astronomy "I have been using it since the day it first became available and I cannot live without it now." - Sedat B., Cloudy Nights forum Feature highlights: • Over 14,000 deep sky objects included, all with closeup reference photos. No need to download anything after install! Sorting and search make it easy to sift through all of them to find which objects belong on your observing list. • Measure your local horizon profile in minutes with your iPhone. • Unique charts completely take the guesswork out of predicting object visibility. Your house, trees, mountains, or any other obstructions are completely factored in to all visibility charts. • New to astronomy? The Featured object list shows a list of objects specific to your location and local horizon that are great for observing right now. • Keep a list of your favorite observing sites, each with their own local horizon profile. Compare object visibility between sites to find the best spot to setup your scope. • There's a lot to observe! Observer Pro gives you a place to maintain a list of your favorite objects as well as an observing list that you can take with you to the eyepiece. • 7Timer! astronomical weather forecasts for your observing sites are viewable without leaving Observer Pro. They give you the outlook on cloud cover, seeing, transparency, and more. • Check out the in-app help to learn more about how to use the many features that come with Observer Pro. Keep up-to-date with the latest news at the Observer Pro blog: http://observer.pro/blog

Mohr’s Circle — Stress Analysis Turn stress inputs into insight. This app makes Mohr’s Circle clear, fast, and interactive — perfect for students, educators, and practicing engineers. Enter 2D or 3D stress components, visualize Mohr’s Circle instantly, compute principal stresses and maximum shear, and export clean, shareable PDFs. Whether you’re checking homework, preparing lecture material, or validating calculations on the job, this tool helps you go from inputs to answers in seconds. What you can do • Visualize Mohr’s Circle (2D) and (3D) • Compute principal stresses (σ1, σ2) and maximum shear (τmax) • Transform stress states with angle controls and see results update live • Inspect clear σ/τ axes, principal points, and helpful annotations • Save and load stress states for quick reuse • Export neat PDFs (current view or full report) to share or archive Designed for clarity • A modern, touch-friendly interface built with SwiftUI • Real-time updates as you adjust inputs and angles • Clean labels and overlays for principal stresses, τmax, and key geometry • Helpful summaries and formula references for learning and documentation For 2D and 3D workflows • 2D: Enter σ11, σ22, τ12 and explore Mohr’s Circle with interactive visualization • 3D: View the triple-circle representation and principal stress values (σ1, σ2, σ3) Save, load, and share • Save your stress states with a title and timestamp • Load them later to resume work or compare scenarios • Export PDFs for reports, review, or teaching materials Upgrading from an older app? • One-time migration preserves your previously saved records from the legacy Core Data store (if present on device) • Migration runs safely once and avoids duplicates Who it’s for • Mechanical, civil, aerospace, and materials engineers • Students learning mechanics of materials and stress analysis • Educators preparing examples and lecture visuals • Anyone who wants a clean, focused Mohr’s Circle tool Why this app • Focused: Everything you need for Mohr’s Circle — no clutter • Practical: From input to principal stresses and τmax in seconds • Shareable: Export clean PDFs for documentation and teaching