There is no Lightroom for iDevices (which run the iOS operating system).
All software for iPhones and iPads must be downloaded via the Apple App Store.
Safari is pre-installed on iDevices.
Chrome download: https://itunes.apple.com/au/app/chrome/id535886823?mt=8
The closest Adobe offers for Lightroom in iDevices is Adobe Revel
https://itunes.apple.com/au/app/adobe-revel/id455066445?mt=8