A trigonometry app helps you learn or use trig on your phone, but most do one job. Some drill unit circle values until you know them cold, some let you drag an angle and watch sine, cosine and tangent change, and some solve triangles from the sides and angles you know. Ten apps follow, in no particular order.
Trig is where a lot of students stop following along. One app on this list was built by a parent whose daughter met sine and cosine at school and asked why she even needed them, after formulas, practice sheets and flashcards had all failed to make it click.
The ten apps below are in alphabetical order, and each description comes from the app's own App Store listing. If you'd like an AI chatbot to talk you through a step you're stuck on, my guide to ChatGPT prompts for maths has prompts you can copy.
Trigonometry apps side by side
I read each app's App Store listing for the free plan column, as of Oct 2026. Yes means the listing shows a free download, though several of these keep extra lessons, calculation steps or an ad-free mode for an upgrade. Not stated means the listing I read didn't offer a free version.
| Tool | Type | Good for | Free plan |
|---|---|---|---|
| Beautiful Trigonometry | Visual explainer with sliders | Seeing why sine and cosine exist | Yes |
| Brainly | Homework help with tutors and AI | Getting a stuck question explained | Yes |
| Calculator + | Basic and scientific calculator | Everyday sums plus scientific functions | Yes |
| Speed Trigonometry | Unit circle drill | Memorising unit circle values fast | Yes |
| The Unit Circle App | Interactive unit circle reference | Checking degrees, radians and coordinates | Yes |
| Touch Trigonometry | Live unit circle and graphs | Linking the circle to all six graphs | Yes |
| Trigonometry calc | Right-angled triangle calculator | Quick right-angled triangle answers | Yes |
| Trigonometry Calculator | Triangle solver | Right-angled and scalene triangles | Yes |
| Trigonometry for Beginners | Levelled beginner lessons | Starting trig from angles and ratios | Yes |
| Trigonometry Identities Proofs | Identity proof practice | Working through identity proofs | Not stated |
Ten trigonometry apps to try
Beautiful Trigonometry
Best for: Learners who keep asking what sine and cosine are for, with sliders, colour and motion showing how angles and sides connect.
Brainly
Best for: Parents who'd like homework help on call, with step-by-step walkthroughs of scanned maths problems and a free tier with limited features.
Calculator +
Best for: Anyone who just needs a scientific calculator on their phone, with the basic and scientific modes both free and extra solvers as upgrades.
Speed Trigonometry
Best for: Precalculus students who need sine, cosine, tangent and inverse values at the four main unit circle angles to come instantly.
The Unit Circle App
Best for: Homework checkers who want to drag a point round the circle and read off degrees, radians, coordinates and the three main ratios.
Touch Trigonometry
Best for: Visual learners who'd like to drag an angle on a live unit circle and watch all six trig functions trace their graphs.
Trigonometry calc
Best for: Beginners with a right-angled triangle to finish, using Pythagoras and the trig ratios to find the missing sides and angles.
Trigonometry Calculator
Best for: Engineers and students solving a triangle for sides, angles and area, in degrees or radians, with results to 14 decimal places.
Trigonometry for Beginners
Best for: Complete starters who want levelled lessons from angle basics through right triangles and special angles to word problems, with instant feedback.
Trigonometry Identities Proofs
Best for: Students practising identity proofs who'd like 42 to work through, writing their own first and then revealing the hidden steps one by one.
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Drill, explain or calculate: pick the job first
Most trig apps do one job, and the job matters more than the app. Drill apps build recall. Speed Trigonometry quizzes you on the values at π/2, π/3, π/4 and π/6 until they come without thinking, and Trigonometry Identities Proofs keeps each step of its proofs hidden behind a button, so you have to try before you look.
Explainer apps build understanding. Touch Trigonometry splits the screen into a live unit circle on the left and graphs on the right, so moving the angle on one side moves the dots on the other, and its listing says users told the maker they'd never understood why the trig functions existed until they used it. Beautiful Trigonometry does the same with sliders and keeps four topics free to explore, including the sine area formula and the law of cosines, with graphs of all six functions and an identities reference on its Pro upgrade.
Calculator apps build nothing, and that's fine when all you need is a finished answer. But a calculator won't teach you the unit circle, and when the test asks for the exact value of a special angle, it has to be in your head.
Using the three kinds together
- Start with an explainer until the circle and the graphs make sense to you.
- Switch to a drill for the special angles, a few minutes a day, until the values are automatic.
- Practise identities by writing each proof yourself before you reveal any steps.
- Use a calculator to check triangle answers you've already worked out, not to replace the working.
Do you make trigonometry or maths learning apps? Tool makers can ask to be considered for a featured place on this list.
My advice for anyone learning trig on a phone
Pair one explainer with one drill and leave the calculator for checking. Once you've seen why the values are what they are, they're far easier to remember, and the drill makes sure you can recall them quickly when it counts.
Most of these apps are free to download, so try two or three and keep the one you'll open without being nagged. For revision beyond trig, my guide to ChatGPT prompts for studying and revision is worth a look.
Want your tool on this list? Featured spots and reviews here are paid partnerships. Here's how to partner with me.
Frequently asked questions
What is the best trigonometry app?
There isn't one best app, because most do one job. Pick a drill app for unit circle values, an explainer app to see how the functions behave, or a calculator to solve triangles.
Is there a free trigonometry app?
Yes. Nine of the ten apps here show a free download on the App Store, as of Oct 2026, though some keep extra steps, lessons or an ad-free mode for an upgrade.
Which app helps me memorise the unit circle?
A drill app that quizzes you on sine, cosine, tangent and inverse values at the main angles is the quickest route. A calculator won't help you remember them.
Can a trigonometry app solve any triangle?
Every triangle calculator here handles right-angled triangles, and some also solve scalene triangles from the sides and angles you know, in some cases only on an upgrade.
