Using Google Drive on Linux is a pain. Insync makes your life easier by providing a native Google Drive client on Linux. Read the complete review.
If you are looking for converting audio file formats to wav, mp3, ogg or any other format, SoundConverter is the tool you need in Linux.
CPod is an open source podcast application for Linux, Windows and MacOS. A clean UI and essential features make it a good choice for listening to podcasts.
Mathpix is a nifty little tool that allows you to take screenshots of complex mathematical equations and instantly converts it into LaTeX editable text.
Cozy is a nifty little audiobook player for Linux. While there are not many audiobook players for Linux, Cozy tries to fill the void to some extent.