Sure!
The two sensors and apps of the same name I'm complaining about are the Freestyle Libre 3 and Dexcom G7. IMO, absolute bare minimum for what is required in an app of this kind is:
- get the glucose level from the sensor and show it in the app, incl. a history graph (even the old dedicated handhelds did this)
- play an alarm when that value is below/above a low/high glucose threshold
The Freestyle Libre 3 does this, and absolutely nothing more. They ported the software from their dedicated device to Android and called it a day.
Frustratingly, this means that you don't even get your current glucose in the notification area, or the lockscreen, or anywhere else. You have to open the app.
You can set the alarm thresholds arbitrarily, but only get 1 high and 1 low alarm setting. Disabling these means you need to go two levels deep into the settings menu. And you WILL be doing that, constantly. Why? Imagine this: You get woken by an alarm for high glucose. You check the app, and see that you've just barely crossed the threshold, but have been hovering below it for the past hour. You take insulin, but of course, that takes time to act. Since sensor measurements are a bit jittery, you can count on the glucose level to dip back below, then back above, below, above,... the threshold for the next 1-2 hours.
The app will blare an alarm at the highest volume your phone is capable of every. single. time. Your (and potentially your partner's) sleep will be interrupted IDK how many times, unless you completely disable the alarm. Be sure to remember switching it back on in the morning, though! :)
The fix would be incredibly simple: either allow muting alarms for a set period of time, or don't play an alarm if it has recently been played and the amplitude of glucose measurements is small.
On the flipside, if you miss an alarm - say you are speaking in a meeting so you swipe away the blaring alarm - you will not be reminded again. My high glucose alert is/was set rather low (150 mg/dl) because that's the point where it makes sense for me to take additional insulin. If that alarm goes off and you dismiss it, it will not go off again (unless you first dip below, as discussed). Doesn't matter if two hours later you are at 160 or 380. Sure, it is also my responsibility, I am not denying that. But again, adding this feature would have been hugely helpful and so, so easy to implement.
Let's take a quick sidebar and talk about hardware. The Freestyle Libre 3 is an AMAZING piece of hardware. It's incredibly tiny - about two pennies stacked, both in diameter and height. Still, it sticks to your skin very well, and measures and sends your blood glucose to your phone via Bluetooth every minute for two weeks straight before the battery gives out. As if that weren't enough, it's also so well-made that in the almost two years I was using it, I did not have a single unit that was defective or ran out of battery in less than the promised two weeks. It's fantastic.
...but sending glucose info every 60 seconds is also a drain on your phone's battery, especially if your app isn't, uh, made well. Take a guess as to where this is going. Ready? Wrong, it's worse. If I would go to bed with 100% battery, I would wake up with 40% left. I needed to charge my phone 4 times a day. Since switching to the Dexcom G7 (imperfect as it is - we will get to it, I promise), that is back down to once a day.
Apart from draining the battery, the app is also slow, and gets really slow the longer you have it installed. This mainly shows itself in the glucose graph being slower to render over time. Deleting the apps data, i.e. starting fresh, makes everything run reasonably fast again. Over the course of a couple of months, a couple hundreds of megabytes of app data accrues, and the app starts to crawl instead of run.
The next part is pure conjecture on my part, but I am still going to share it. My theory is that every time you open the app, the entire graph history is computed from scratch. That would explain the amount of data <-> slowness relation, and probably at least partially account for the battery drain.
In short: Freestyle Libre 3 (the hardware) is fantastic, Freestyle Libre 3 (the app) does the bare minimum and sucks at it.
You can not use it with xdrip+, except by installing a cracked version of the original which exposes the current glucose level through a webserver on your phone, and an additional app which grabs the values from there and passes them on to xdrip+. This is error-prone and does not exactly help with the battery drain.
On to the Dexcom G7. In the next comment, because apparently there's a 10k character limit on comments.