lex@critiko.com is the address to write to.
Support
We answer, personally.
Questions about Lex, your books, or Pro — a human reads every message.
Contact
Email us
FAQ
Honest answers
Which file formats are supported?
EPUB, PDF, CBZ (content-validated image ZIP), and TXT. CBR/RAR, OPDS feeds, and Markdown are not supported.
Where do my books live?
In your Files app — on your device or in iCloud Drive. Lex opens them in place and never copies or uploads the originals.
How do I import files?
Pick files from the Files app, share files into Lex from other apps, or use Wi-Fi import to move books from a computer on your network.
Is basic reading free?
Yes. Reading every supported format, the library, imports, Wi-Fi import, themes, bookmarks, and reading progress are all free.
What does Pro unlock?
Exactly three things: Sharper pages (on-device upscaling with MetalFX), iCloud sync, and manual wide-page splitting. Nothing else is gated.
Is there a subscription?
No. Lex is free, with one optional one-time Pro unlock. There are no subscriptions and no ads.
How do I restore Pro?
Open Settings in Lex and choose Restore Purchases while signed in with the same Apple ID you used to buy it.
Does Lex upload my books?
No. Your original files stay in your Files app and reading data stays on your device. The only data that leaves is opt-in usage analytics (off by default) and anonymous crash diagnostics that are always on when the app crashes — two separate paths, and neither ever includes your books, titles, contents, highlights, notes, or anything identifying.
Which devices are supported?
iPhone, iPad, and Apple Silicon Macs through “Designed for iPad”. A native macOS app isn't available yet.
Privacy
Where your data lives
Your books stay in your Files app and reading data stays on your device. Analytics is off by default, and anonymous crash diagnostics are always on when the app crashes. Content is never sent on either path. The full story: