I have recently installed the latest APK version of Pokemon Go (0.37.0). When I opened the app and signed in, it showed me a message saying my device isn't compatible with Pokemon Go.
My device isn't rooted, and I have a Huawei G7 with Android version 4.4.4, however the game still refuses to let me in.
Best Answer
As you know, Niantic occasionally releases new versions of Pokemon Go. In order for those changes to not be a buggy mess, developers and testers have to ensure the latest changes work on a whole bunch of devices, as well as various versions of Android and iOS.
Here's the catch: If Niantic continued to support every old device, the effort of developing for and testing would grow over time, as more and more devices are released. This would be a costly exercise and would slow down development time significantly. Furthermore, it's likely that the game would be unable to take full advantage of new hardware and software features, as they would need to cater to the lowest common baseline of the older devices.
So what actually happens is Niantic occasionally drops support for some older Android/iOS versions and devices. I can't say for sure, but this is likely based on a couple of factors:
What doesn't Niantic support?
As of July 2019, Niantic has ceased support for:
The currently supported technical specifications are as follows:
See Niantic's 'Supported Devices' Page for more information.
What does this mean for your device?
Assuming your Huawei G7 is the Ascend G7 - Android version 4.4.4 is no longer supported by Pokemon Go. However, all is not lost: you might be able to upgrade your system version to Android 6 and get it to work. I would still recommend looking into getting a more modern device if possible, as it is likely not long until that phone falls completely out of support.