Due to international security requirements we follow, we currently allow offline access just for iOS devices. When you use the SeriousMD app on your iPhone or iPad, you'll be able to access it offline.
If you'll use the app offline more often, we recommend that you sync the app regularly so there's always a backup. Basically, the next time your device detects an internet connection, it will connect and backup the data you might have added offline. That way, no matter what happens to your device, you can just get a new device and download your database there.
When accessing it on the browser on any device, including your laptop, we won't store any data on the computer, so you won't need to worry about space. You'll just need internet.
You can also use both the web version and iOS version at the same time and it will sync together seamlessly.