What's the Difference between Free Version and Paid Version of PDF Reader Pro?

PDF Reader Pro Free is the free version, which locks most of the advanced features. PDF Reader Pro offers you advanced features with a smooth and perfect reading experience. Subscribe Individual Plan to experience effective PDF reading, or you can get the Permanent Plan to make full use of all the advanced features once for a one-time purchase.

Now, you can experience a 7-day free trial to enjoy PDF Reader Pro before you purchase it.

 
You can refer to here to compare the features of the various PDF Reader Pro plans.