Change PDF viewer to Reader. If at all possible. It will make the app more powerful. The paid version with a reader and document editor
If at all possible. It will make the app more powerful. The paid version with a reader and document editor will make it worth the money and make it live up to multi-tasking functionality while on the go. Also any chance you can also add Facebook Messenger or other popular messaging Apps (WhatsApp or Skype)? I think that would be much more functional than having apps preinstalled on the phone that aren't normally used during regular browsing experience.
I’m not sure if I understand you well, but PDF viewer is part of document viewer. So there is only one viewer capable of opening typical document formats.
It’s not possible to float normal apps due to Android limitations and this is also reason why we simply can’t – we would love to, believe me – add whatsapp, skype and other. It cannot be done :-(.