Dexcom app and spike app running at the same time?

You can force the xDrip app to mirror the readings of the Dexcom receiver. It’s an option called Native Algorithm. When I’ve used it (seldom), it makes the xDrip app require a 2 hour warmup if I restart a G5. Using the OB1 algorithm instead, xDrip will continue to show data for as long as a sensor is installed, be it 7 days, 10 days, 20 days…

Does xDrip/Spike provide useable blood glucose readings in the initial 2-hour warmup period of a sensor or only when you are restarting a sensor?

My xDrip+ was set to “Native Algorithm” when I took that screen shot and that is the default setting. I think the only thing I have changed from the xDrip+ defaults is to set “Unbond G5 before each read” and I only did that a couple of days ago because I found that my phone was dropping the connection to the transmitter in the car, possibly because the phone connects to two extra bluetooth devices (so four total) when in the car.

I agree with what you said - the jumping around might potentially lead to under or over bolusing. On the other hand it was happening when I was moving around a lot in the stores and I wasn’t going to do a bolus then - I was doing something else!

That said, the big jumps were about 10%, my blood sugar was quite high, and xDrip+ reported readings much closer to the trend in 10 minutes (two readings). I’m generally very happy with xDrip+ so far. BTW - the high (yellow) line on the xDrip photograph is actually at 170mg/dl, while I had the Dexcom receiver set to 180mg/dl so the dots on both displays seem to be in the wrong place, given the ‘now’ reading of 164 mg/dl,

You can set xdrip to provide readings long before a 2 hour warm-up. I usually set mine to provide readings within the first 30 minutes. Some times a sensor gives decent readings within 30 minutes. Other times it might be flaky for a whole day. Another thing to do is install a sensor using an expired xmitter, and let it soak for a few hours prior to the time that a previous sensor is going to be stopped. When the previous sensor is finished, stop sensor, move the xmitter to the new sensor, set xdrip to provide data within 30 minutes. Use the OB1 function in order to get readings prior to 2 hours.

Another point, somewhat off topic, is that our blood glucose does go up and down in response to environmental conditions. We may not be able to produce insulin but we do still produce glucagon in our pancreata. Glucagon production causes rapid rises in blood sugar which would normally be inhibited by insulin production, which switches off glucagon production as a side effect. Our insulin production mechanism is dead so we don’t do that - the other factors that stimulate or inhibit glucagon production would therefore be expected to produce bigger spikes or dips in blood glucose.

I’ve had no problems running Spike concurrently with the Dexcom app on my iPhone X. Its been almost two months. I have to limit background apps to keep my readings from the Dexcom app coming in- IG etc seem to get in the way. I have been told that running the two apps together is not possible and not recommended. SO, I am not recommending it but I do it, it works for me, and I get two points of reference fro my BS on one device. For what its worth.