Think of it this way. When you are connected to the internet and open the app, it performs a sync to download all of the data to your device into a temporary cache that only exists while the app is open. Also, the data does not store images, but rather the url to the image. Those images are only downloaded and stored in your cache when they need to be displayed in your app.
Now the offline capability comes into play if you already have the app open, because much of the data is already cached on your device. If you temporarily lose internet, the app won’t shut down, but rather it will continue to run…but it can only work with the data that was cached prior to going offline. Although, every time you open the app fresh, it needs to perform this initial synchronization. If there is no connection, then it can’t retrieve data and won’t open.
If you have a business plan or higher, you do get the added ability to add rows while offline, but you cannot edit any existing data because eventually it has to synchronize Glide’s copy of the data (and any third party data source) and if things change before the connection is restored, your data could get out of sync.
First and foremost, these are web apps. Key word…web. Web apps run on top of a web browser…even when “installed”. You may get partial functionality if you temporarily lose internet while using the app, but for the most part, a connection is required to have full functionality.
Regarding this…Glide has two products. Apps and Pages. Glide is in a long term process of phasing out Apps and migrating to Pages. Long story short, Pages will become the only product, but will also be better and more capable than the current iteration of Apps. Apps in their current state will not receive additional improvements, while Pages will continue to evolve. Eventually Apps will merge into Pages, and the Page name will become Apps.