I can't save my app on SD card

Developers of Android apps need to explicitly make their apps available to move to the SD card using the “android:installLocation” attribute in the element of their app. If they don’t, the option to “Move to SD card” is grayed out.

I wonder all the apps I am installing can’t be saved to my SD card. This is the reason. They should be programming that first and making sure it can be saved.

Agreed. Apps cannot be saved on memory card when it is not properly programmed. You really need a high storage on your internal memory.