Elvis Frog

With a rope in your hands the question is never just how to tie it, but whether it will hold - and how it lets go when it doesn't. Elvis Frog answers that by mechanics rather than folklore: choose a rope material, set the diameter, dial in the applied load and mark the line wet or dry, and a deterministic model scores every knot for holding-strength efficiency, slip risk and jam risk, with the formula behind each number 🔢 opened up beside it.

Each of forty-four knots is tied through an interactive builder - swipe 👉 forward and back through numbered steps, every stage drawn as a rope diagram 📊 with the over-and-under crossings correct and a progress 📈 bar tracking where you are in the sequence. Change the rope beneath a knot and the whole rating re-computes in place. Feed a knot into the load simulator and a field of tension particles flows along its path, thickening and quickening as you push the load slider, then resolves into a per-segment strain report 🧾 that names the peak-stress point outright.

Every knot has its own page: its family, its difficulty 📏, the jobs it is meant for, a plain summary and a live rating snapshot against your default rope. Every material carries its own physics - nylon, polyester, manila, polypropylene, Dyneema and cotton each have their tensile strength, surface friction, stretch and wet-strength behaviour, so the same knot ranks differently on every line. The catalog holds all forty-four across six families - loops, bends, hitches, stoppers, bindings and lashings - searchable and grouped by category.

The workbench 🛠️ remembers what you have actually learned. Mark a knot mastered and it counts toward per-category mastery ⭐ rings; every drill is logged and dated, so a category reads as a learned-or-not checklist and each knot keeps its own practice 🏋️ history ⏳ and notes. Tie one for real, photograph it, and the picture is kept on that knot's practice log. Progress survives every restart.

Everything runs on the device 📱, with nothing to sign up for and no connection required. The rope-strength figures are presented as educational estimates for learning, never certifications for life-safety rigging. Units switch between metric and imperial, the default rope and diameter are yours to set, photos 📸 can be removed at any moment and haptics can be turned off - all offline 📴. Elvis Frog keeps the entire workbench focused on practical knot learning.

Key features:

* Mechanics-driven rating: pick material, diameter, load and wet or dry, and every knot is scored for holding-strength efficiency, slip risk and jam risk - with the formula shown
* A step-by-step tie builder for 44 knots, each stage a rope diagram 📊 with correct over-and-under crossings and a progress 📈 track you swipe 👉 through
* Load simulator: a live tension particle-field that responds to the applied-load slider, resolving into a per-segment strain and peak-stress report 🧾
* Six rope materials - nylon, polyester, manila, polypropylene, Dyneema and cotton - each with its own tensile, friction, stretch and wet-strength model
* Catalog of 44 knots across six families - loops, bends, hitches, stoppers, bindings and lashings - searchable and grouped by category
* Knot pages with family, difficulty 📏, use-cases, a plain summary and a live rating snapshot against your default rope
* Custom rope-diameter, applied-load and wet/dry controls that re-score 🔢 every rating in place
* Practice 🏋️ tracker with per-category mastery ⭐ rings, a dated drill log 📝 and per-knot history ⏳ and notes
* Photograph a knot you have tied and keep the picture on its practice 🏋️ log 📝, on the device 📱
* Educational estimates, clearly flagged - a workbench 🛠️ for learning, never a life-safety certification
* Metric or imperial units, default rope material, default diameter and haptics - all switchable, all offline 📴