Mozilla on Thursday formally released(Opens in a new window) version 3.0 of its Firefox OS Simulator, a tool for developers to test apps for the Firefox operating system from their Windows, Mac, or Linux computers.

The company unveiled a preview version of the simulator in mid-March, but has now made some updates and launched a more stable release.

Among the updates Mozilla added in the last 1.5 months are a keyboard shortcut that allows for repackaging, reinstalling, or restarting a current app, “drastically improving workflow speed, especially for packaged apps,” Mozilla said.

The company also promised a significantly reduced download size for the Firefox OS Simulator, as well as a faster start time. There are also much newer versions of Firefox OS and Gaia, as well as general bug fixes.

The updated simulator is available for download(Opens in a new window) on Mozilla’s website.

Firefox OS Simulator launched in November(Opens in a new window), and each new version includes features that target the most common and needed requests. Version 3.0 comes with push to device, a fairly self-explanatory function that allows developers to connect via USB a device supporting Firefox OS, then push apps installed on the Simulator directly to the connected machine.

The OS is expected to launch on commercial phones built by Alcatel, LG, and ZTE this summer in Brazil, Colombia, Hungary, Mexico, Poland, Serbia, Spain, and Venezuela. Phones from Huawei will follow later, as will other country rollouts. The U.S. probably won’t see a Mozilla Firefox phone until 2014.

Developer phones went on sale last month and were quickly snapped up.

For more, see PCMag’s first look at Firefox OS during MWC, and our hands on with the Alcatel One Touch Fire Firefox OS Phone.