It won't replace the desktop version of the program, but users can make simple edits on the go and they will always have access to their latest photos as the app constantly syncs to the cloud.
The app allows users to adjust exposure, color temperature, highlights, shadows and saturation. It also has the crop tool and Adobe's built-in preset tones. There are limits, though, since users will not be able to directly tweak the tone curve, modify individual color attributes or use custom presets.
There may be an app update down the road that will have more detailed tools but Adobe intends for it to be a companion and not a replacement to the desktop version so users will want to go to their desktop to finish their edits.
The app is free to download but to use it a Creative Cloud membership is required, which is at minimum $9.99 per month. Even those who have purchased Lightroom 5 will not be able to use Lightroom mobile without a subscription.