/tmp flooded with .myapp files

I noticed a ton of *.myapp files in /tmp. The content reflects Piwik:


Any way that I can limit the amount of files it creates? Or, anyway to have Piwik clean them on a regular basis?

This all originated from a full disk error message somewhere else on the OS.

Piwik does not create .myapp files so it must be another file - search on the web for hints