It helps to translate from language to others.

Basically, there are lots of pdfs that may not be available in the language we want to read or that we understand. Even when presenting stuff, if the pdf isnt in the required language it just ruins the whole thing. So in such cases a translator is a very handy tool. Now either you can code the whole interface which may seem a lot of hassel or I think a better idea would be to just incorporate the google translate into the adobe acrobat reader just like the delivery apps use the google maps to show the location of package. This saves tons of time plus this is a major feature so you can maybe make it a premium service but i think people wont subscribe just to translate as one can always copy and paste, but company officials will definately go for it as this simplifies their work. Obviously its upto you guys to decide whether to implement this feature, make it a charged service or let it be free, use google's translator or code your own one. I am just suggesting this idea as currently no other reader has this and using this as a paid service can make you tons of money from universities and companies but not normal users. If a client sends me a pdf from lets say Japan and i have to present it to my company, this just makes it way way easier. I am saying this from a student's point of view as this way i can view some other countries' university pdfs and what not, very easily. Please consider this idea