The problem I wanted to solve starts when the readings change. A doctor may ask, “What did you eat around that time?” With this app you can save a photo of the meal alongside the blood sugar reading, notes and medication.
So the goal is less about storing the number and more about keeping the context around the number and making that context easy to share with the doctor.
The most humble meters come free in a kit, since you're really buying the test strips, and they all have onboard memory and an optional app.
It's extremely unlikely the owners of those meters would even be able to use any other app. There's no standard for the device data sent over bluetooth to the app. There's no USB port. Beyond 90 days of data (many meters have 99), A1C is preferred. Reverse engineering to support alternative apps is also unlikely since there are always new devices to hack.
SugarTrack, and other apps like it, sit in a weird deadzone. The most likely users either have a nicer meter that already does offline export, or they have a crappy meter but prefer the official app or tracking their stats on paper anyway (in their food journal). Again, the app is always optional unless it's from a super sketchy brand that isn't even cheaper.
There's no room left for doing weird somewhat low-tech things in principle anymore. The market has moved on. The most common layperson user wants integration across all their health apps. The most common nerd user buys the nerd device. The manufacturers have known this for at least a decade.
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'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.
The world is your oyster if you have some self motivation.
CGMs use the interstitial fluid in (usually, although people also use other spots) inside side of the upper arm to measure blood sugar. As long as they are placed in the right spot (i.e. in a fattier area instead of directly on top of muscle, hence why it is on the inside side of the upper arm and not the outside) and the sensor doesn't fail, they will measure blood sugar fairly accurately for 10-15 days depending on the CGM model (disclaimer: They do tend to run approximately 15 minutes behind the number that an actual finger poke would show you).
Nightscout is an awesome tool because it can be self-hosted so that you keep full control over your health data, but since it is a web application, you can still easily share it with other people too, like family or your endocrinologist.
On android, you can use the xdrip+ application to pair with most types of CGMs to completely keep your data out of the cloud, or you can also pair it with the API from Abbott or Dexcom (depending on the CGM model) to pull data from their 'share/link' applications, if you opt to pair with/use their official apps
[0]: https://nightscout.github.io/ [1]: https://github.com/nightscoutfoundation/xdrip
I personally use Dexcom G7 15 day sensors (because it is what my insurance covers) and use xdrip+ to upload the data to a nightscout instance hosted in my homelab
It must be a different kind of device.