WordPress CMS has a nice auto update feature that displays update notifications for outdated plug-ins and themes in admin panel. Once you got a notification you can go to Dashboard->Updates and install all updates with few clicks while WordPress will automatically download and extract archives, remove old versions and reactivate plug-ins for you.
The only problem is that it works for plug-ins published on wordpress.org which are open-source so it’s not an option for commercial plug-ins.
Luckily there is a very good solution to this problem: Upgrademe plug-in.