For many many years, Microsoft has provided light weight tool sets for building pseudo applications. These have included Microsoft Access, Lightswitch, Silverlight, InfoPath Forms, and various other technologies targeted to developing line of business applications without the need of “custom” development.
The latest platform was announced today – PowerApps is a brand new cloud based platform that enables organizations to develop applications that leverage cloud services such as Office 365, Dynamics CRM, SalesForce, DropBox, etc. and present data through rich user interfaces already responsive for various device form factors.
There isn’t much information out yet but it looks like the service is based on Project Sienna which has some more extensive documentation.
Here are some typical applications you could build with this platform.
Catalog Browser Applications
Content Browser Applications