Errors create doubt
You reread a message because one typo or awkward sentence can change how it sounds.
AI grammar checker keyboard for iPhone
Fix grammar, spelling, and style as you type.
Checker is an AI writing assistant for iOS that improves complete sentences without making you leave Messages, WhatsApp, email, Notes, or other apps.
Free to download · Requires iOS 17.6 or later
Built for everyday writing
For anyone who types on iPhone
StudentsMultilingual writersWorking professionalsContent creatorsEveryday iPhone users
The problem
Your message is clear in your head. The wording is not.
Editing breaks your flow
Copying text into a separate grammar checker takes longer than writing the message.
Autocorrect misses context
Word-by-word corrections do not understand the meaning or tone of a full sentence.
The solution
A grammar checker where you already type
Checker reads the sentence you choose, corrects it with context, and lets you insert the improved version back into the current app.
Works from your keyboard
No separate editor and no repeated copy-and-paste workflow.
Checks complete sentences
Corrects grammar, spelling, punctuation, and unnatural phrasing together.
Preserves your meaning
Improves clarity while keeping the original intent, language, and message style.
How it works
Three steps. One cleaner message.
- 1
Install the keyboard
Download Checker and enable its iPhone keyboard.
- 2
Type in any supported app
Write your message, email, note, or caption as usual.
- 3
Run Checker
Choose the text, select a style, and insert the improved result.
Core features
Everything needed for clearer writing
Grammar
Fix sentence structure and common language mistakes.
Spelling
Correct typos before they reach the conversation.
Punctuation
Add the punctuation needed for natural readability.
Rewrite
Rephrase awkward sentences while keeping their meaning.
Tone
Choose friendly, formal, casual, polite, or flirty wording.
Translate
Translate directly from the keyboard without switching apps.
Before and after
From uncertain to ready to send
Hey I wanted ask if you free meet tomorrow?
Hi! I wanted to check whether you’re free to meet tomorrow.
App Store reviews
4.7 average from 34 ratings
Feedback from Checker users around the world.
★★★★★Recommended app!
“Useful for messaging in multiple languages. It corrects and translates sentences accurately, with a beautiful and intuitive design.”
★★★★★Very convenient
“I use it often and it rephrases text well.”
★★★★★Great at correcting mistakes
“I liked it—very convenient! I never thought an app like this could be so easy to use.”
★★★★★100% worth it
“Writing in a foreign language always made me anxious because I feared not being understood. Not anymore. Thank you!”
★★★★★Perfect
“Exactly what I was looking for. It makes writing in any language easier and helps me write without being afraid of mistakes.”
Privacy and transparency
Know what the keyboard needs
You choose the text
Checker processes text only when you start a check or translation.
Internet is required
AI checks and translations need an internet connection and iOS Full Access permission.
Clear privacy details
Read how data is handled in the published privacy policy before enabling the keyboard.
Read Privacy Policy →FAQ
Questions before you install
Does Checker work in WhatsApp, Messages, and Instagram?
Checker works as an iPhone keyboard in apps that allow third-party keyboards, including common messaging and social apps.
Does it work with Apple Notes and email?
Yes. You can use Checker in Notes, email fields, and other editable text areas that support third-party keyboards.
Does Checker require an internet connection?
Yes. Grammar checks, rewrites, and translations use an online AI service.
Is my text stored?
Checker sends the text you select for processing when you request a check. The service is configured not to store AI responses.
Which languages does Checker support?
Checker detects the language of the text and keeps that language when correcting it. The app interface is available in English, Italian, Portuguese, Russian, and Spanish.
Is Checker free?
Checker is free to download and includes limited AI checks. Optional Pro purchases unlock higher limits.
AI writing assistant for iOS
Send cleaner, clearer text from your iPhone keyboard.