Infinite Flight is a graphics intensive app, we’ve always been clear about this. Mobile devices will get warmer (as does any technology) when under any load.
If your device is getting too warm, it’s a sign that the settings are set too high for the device. Some Android distributions throttle components in the device to compensate for this, which normally results in a frame rate decrease. If you are being cautious about the battery, turning down settings should help, although in our extensive usage we haven’t found any significant impact to device battery.
We’re working with each iteration of the app to improve our footprint and optimise the app. In 20.1, we made changes to lower CPU usage on longer flights to lower the strain on the device, and we’re continuously revisiting parts of the app to optimise things as much as possible.
Project Metal has the potential to bring more improvements to this, although it’s too early to tell.