Browsers that won’t work: Unfortunately, PicMonkey no longer supports Internet Explorer 8 or earlier versions. We recommend upgrading to Google Chrome or a recent version of one of the other browsers listed above. If you have IE 9 we encourage you to update to the latest version of IE, as many of the updates you are missing out on are security patches.
Mobile devices: Because they don’t allow Flash, your iPhone, iPad, or other iOS devices won’t run PicMonkey. But an Android mobile device will run PicMonkey if you have Flash installed on it.
If you have an older Mac:
If you have OS X 10.6.8 or newer, Apple is currently offering a free upgrade to 10.9 Mavericks. We encourage you to take advantage of this offer as it allows you to get the latest Safari versions and a pile of security updates. For more information see this information from Apple.
If you haven't upgraded to 10.6.8 (Snow Leopard) yet and have an Intel processor you can buy the upgrade to Snow Leopard from the Apple store for $20. Once you upgrade to Snow Leopard you can get the free upgrade to Mavericks. Click here to get Snow Leopard:
Unfortunately for PowerPC processor systems, Mac long ago stopped supporting these platforms and upgrading to Snow Leopard or Mavericks is not possible.