SystemPal (previously named MemoryTool) is the best tool to monitor your memory/CPU usage status, CPU temperature and fan speed. With this app, you can just click a button to free the wasted memory. You need not spend money buying more memory modules.
v5.2 [Oct 19, 2016]
1. Made the UI look good. Supports macOS Sierra.
2. Supported macOS dark mode!
3. Removed mini music player’s ugly background.
4. Made other minor fixes.
5. The Contact Developer email will have the diagnosis info which does not contain any personal info and helps us solve problems. You can remove it if you don’t want to share it to us.
6. Because the per-process network monitoring does not work well on macOS Sierra, we have removed this feature.