1. If you purchase in the free version, PDF Reader Pro - Lite Edition from Apple App Store, but still cannot access advanced features. Please Restore Previous Purchase.
2. If you buy the paid version, PDF Reader Pro - Sign,Edit PDF from Apple App Store, you don't need to restore previous purchase. But if you have purchased PDF to Office Pack inside the app but still cannot convert PDF to Word/Excel/PPT, you need to restore the purchase. If you have not purchased PDF to Office Pack, you can only convert the first 10 pages.
All transactions are bound to your Apple ID, so you can restore your previous purchase with the same Apple ID account that you previously used. And the steps are as follows:
1. Open the app and go to Settings;
2. Click the banner on the top, then click Restore Previous Purchase;
3. Once you see a “Restore Successfully” message, you will be able to access the advanced features, including PDF converting, watermark, OCR, audio notes, TTS and more, according to your purchases (Premium / Permanent License / PDF to Office Pack).
If it shows “Unable to Restore Purchase”, please make sure:
1. You use the same Apple ID previously used to purchase in the app.
2. You've made a valid purchase. You can check your purchase history to confirm your service pack.