I think we might be able to assume that in the current state of the Web, if we do not own and control the servers where the data is being processed, we cannot be 100% certain what actually happens with the data.
No it is not impossible since you could develop an App that did not store personal data.
As a reminder, the principle of GDPR is that you need the permission of the user to store (safely) and use their information (for clearly defined purposes) plus you need a mechanism that allows you to respond to a request to delete the information in a timely fashion. All of which is completely manageable depending on how you design the App. Hence, with due diligence most Apps are possible.
If a user request is received then the owner must have a process to delete the user’s data, a task that is abundantly clear for experienced App developers.
You should be able to develop a project on Glide and be reasonably comfortable that you are doing so according to EU regulations. Up to you to comb through the legal information provided by Glide and decide for yourself if the terms and conditions work for you:
As I said above, I would argue that you cannot actually guarantee that all the data associated with a user is purged from Glide. Currently, you can only trust Glide – and other online service providers for that matter – that they are indeed deleting the data, but that is anyone’s guess. This point of view might be a little cynical.
For a more practical approach, this is how you would delete all the data associated with a user within your Glide project:
Head over to “Settings > Data”
Delete the user’s data there by entering their email.