For those reading this thread and confused about the new metadata keys, X-OD-NeedsDownscaling and X-OD-NeedsGSensor:
Adding X-OD-NeedsDownscaling=true to a .desktop file, by itself, will NOT make an application use the IPU. Please do not unpack OPKs, add this key then repack them. It would be a waste of time. The key is a hint to the system that your code may need some things that would hinder performance if enabled for all applications, such as 640x480 software rendering.
One needs to add the SDL_SetVideoMode call to their code, with over-320x240 dimensions, and set X-OD-NeedsDownscaling (or simply use under-320x240 dimensions without setting the key), to form an OPK that properly uses this feature.
Adding X-OD-NeedsGSensor=true to a .desktop file, by itself, will NOT add accelerometer support to an application. Please do not unpack OPKs, add this key then repack them. It would be a waste of time. The key is a hint to the system that your code will open the g-sensor, which is better to leave off if unused due to its power consumption.
One needs to add the key, then open and use the accelerometer as a joystick with the name "mxc6225" in their SDL event loop in code. Other chip names may appear in the future for this joystick if the factory decides to change the chip.