Oxios Memory is a free utility suite for Windows Mobile pocket pcs and smartphones consisting of two applications.

One is Oxios Hibernate which sends WM_HIBERNATE to all applications running on the Smartphone.

WM_HIBERNATE is a window message that is generated by the Windows operating system and sent to an application when system resources are running low. All applications should get the message and handle it by attempting to release as many resources as possible by unloading processes, destroying windows, or freeing up as much local storage as possible without damaging the internal state of the system.

The second app is called Oxios CloseApps.
Each process started on a Windows Mobile-based Smartphone allocates memory, which cannot be released but is automatically freed when the application process ends.
Oxios CloseApps closes down all applications by sending WM_CLOSE messages to all running applications