I tested Tweeter on hardware from 2005 - 2011 and the conclusions were that it's 60% faster than opening a browser and going to Twitter.
Using Tweeter lets your system relax by using less resources than a common browser tab.
You can tell Tweeter to stay out of your way with minimise at start-up and minimise to system tray options.
Tweeter uses the Gecko engine commonly found in Mozilla's Firefox for a fast, fluent browsing experience.
Tweeter is completely safe to download and comes with a lifetime of free updates from when you download it to give you the most up to date features and fixes, this also includes service packs.
If you're worried, I have ran it through VirusTotal for you: VirusTotal Results
Current Version: 188.8.131.52
Size: 29.0 MB
Compatibility: Windows 7, 8.1 & 10