PlainPen: AI Writer & Editor

Email Replies & Text Rewriter

Only for iPhone

Free · In‑App Purchases

iPhone

Have the words, but not the wording? Rewrite an email, shape a reply or turn notes into a draft. Follow up to adjust the tone, then choose what to keep. Turn a rough message into a clearer email. Find a reply that sounds like you. Turn your notes into a first draft. PlainPen is an AI writing assistant for iPhone. Start with your own words or materials, then ask for a shorter, warmer or more professional version. Keep working in the same conversation and review the result before sharing it. EMAILS AND REPLIES Draft an email, rewrite a difficult message or prepare a reply from text or a screenshot. Add a follow-up to change the tone, length or audience. REWRITE WITH CONTROL Rephrase a sentence or work on a longer draft. The document editor offers suggested changes, comparison, undo and version history, so you can choose what to keep. START FROM YOUR NOTES Bring in source material to draft, summarize or translate. Import TXT, Markdown, DOCX, text-based PDF, PPTX and XLSX files. Selected materials are shared with the AI for the task; review extracted text and any references. MAKE IT SOUND LIKE YOU Save writing preferences, tone rules and expressions to avoid. These guide the assistant; they are not a guarantee that every suggestion will match your intent. KEEP YOUR WORK Revisit conversations and saved documents. Export documents as TXT, Markdown or DOCX. Local document editing and export work offline. AI needs an internet connection; you can try the free AI Chat allowance without signing in. Sign in with Apple is used for subscriptions and a recoverable account. FREE AND PRO Start with 20 successfully completed AI replies per UTC calendar month. PlainPen Pro includes 300 per UTC calendar month on either the monthly or yearly plan. Follow-up replies count toward the allowance; background summaries do not use an extra reply. Unused replies do not roll over. Subscriptions renew automatically unless canceled. The price and billing period shown by Apple apply. Manage or cancel your subscription in your Apple account settings, or use Restore Purchases in the app. AI requests send the content needed for your task to our service and AI provider after your consent. AI can change details or make mistakes. Check names, dates, amounts and references before using an answer. Privacy: https://plainpen-api.mapp012-server.workers.dev/privacy.html Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

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The developer, 于川 曹, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Linked to You

    The following data may be collected and linked to your identity:

    • Purchases
    • User Content
    • Identifiers
    • Usage Data

Privacy practices may vary, for example, based on the features you use or your age. Learn More

Accessibility

The developer has not yet indicated which accessibility features this app supports. Learn More

Information

Seller
于川 曹
Size
4.6 MB
Category
Productivity
Compatibility
Requires iOS 17.0 or later.
  • iPhone
    Requires iOS 17.0 or later.
Languages
English and Simplified Chinese
Age Rating
18+
In-App Purchases
Yes
  • PlainPen Pro Yearly $69.99
  • PlainPen Pro Monthly $14.99
  • Learn More
Copyright
© 2026 Yuchuan Cao
  • Privacy Policy

    • More by 于川 曹

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