Hi Mark,
App Dev and App Run are 2 out of box metrics defined on application level depending on the drivers. App Dev can be labor costs allocated through Application/App Dev Sub tower or direct costs from a specific project. App Run is everything else other than App Dev expenses, to support and maintain that specific application. So the total should give us the total app cost. When you look at the help for these sub tower definitions:
Application Development
Resources involved with the analysis, design, development, code, test and release packaging services associated with application development projects
Application Support & Operations The operations, support, fix and minor enhancements associated with existing applications
Hope this was helpful!
Aydan