> It's extremely unlikely that owners of these meters would be able to use any other app.
I've been using Xdrip+ for 2 years now with the Dexcom CGM instead of their proprietary app. Works great and gives me the ability to export my data or sync it with a self hosted database if I so please. Why would I trust a corporation with my private health data when they have continuously shown that they will sell it or lose it to a hack the first chance they get.
I've used Xdrip before, and it's device support is not that great either.
I'm not arguing against the idea. I'm being realistic about what devs and users can do about this situation.
If you're lucky enough to find something that works, I'm not knocking that.
You might want to consider using a self-hosted database to store your data. Telemetry Blocklist (free) can help prevent any apps from phoning home, but it's not specific to this use case. If you're concerned about data security, you might want to explore other options for storing your health data offline.