Lightroom Mobile's premium subscription costs about USD $5/month depending on your region, and provides 100 GB of storage. With this, you are able to access your subscription via another Android or iOS device, or also lightroom.adobe.com in any browser. The subscription is currently mobile only, and does not provide access to the desktop apps -- for those please visit adobe.com or desktop app store for additional options.
If you subscribe on any platform, and then cancel, photos in cloud storage will be preserved for only a limited time; I'm not sure exactly how long, but believe it's more than just a few days. If you want to immediately purge your account upon cancellation, we can help. Hope this helps a bit. Thank you!