After 500k Apps Built, Bizness Apps Launches Apex, a White-Label App Builder
techcrunch.com
techcrunch.com
This blog post is a bit old but shows around 1.25mm apps on the iOS App Store at the beginning of 2015.
http://blog.appfigures.com/app-stores-growth-accelerates-in-...
I also think 500k apps is either a heavily padded number or has an extra 0... I doubt one company accounts for more than 33% of apps.
You can create beautiful crud apps or rest endpoints for your entities in minutes