It seems like a major Windows 10 Store bug that shows apps updates when there is none.
In a mega Apps updates push that may signal something significant like Windows 10 Mobile release to non-insiders, my Lumia 640 XL is showing update availability for as many as 31 apps. There is a big list of which all apps have been updated and it includes both native and 3rd party apps.
Windows Camera, Groove Music, Films & TV, People, OneDrive, Messaging + Skype, Office Apps, MSN apps and 3rd party apps like WhatsApp, Facebook Beta have also seen updates. We will update you with what has changed in the apps once we are done with updates.