If you have an older generation iPhone, such as iPhone 3G or 3GS. You may notice, after 2-3 years of usage, that the OS runs sluggish and may even crash. Its well known that improvements and upgrades to the OS may allocate more memory, and having a nice little multitasking tool is nice. But its going to eat up memory fast.
Core Monitor (Free) is a nice little application for iPhone that lets you visualize current memory usage. As well as monitor:
- Remaining Battery (Roughly)
- Disk Usage
- CPU Load
- Running Processes
- Device Information (Slightly buggy in my experience)