Default [Q] Frequent Apps Exit/Crash

Hi,

I just got my brand new Moto G 16gb KitKat 4.4.2 few days ago, installed apps such as FB, Linkedin, Whatsapp, MS Office, Clash Of Clans, normal apps/ games that average user will use.

My phone started to have this strange problem where application will exit it self without warning or will crash upon loading up.

For example, whatsapp would not push the message to me until i open it, like its background service is not running, games half-way loading will exit itself without warning or crash and force to close, Battery widget running/displaying in status bar close it self.

My current available memory after awhile using FB, browsing, games, is roughly around 285 - 240MB.

I suspect this is something to do with memory since it seems to be okay after a restart? I tried to Google it but can' find anything about this, is there any one here know what is wrong?