This app was mentioned in 21 comments, with an average of 1.19 upvotes
Here's what it looks like on my screen
I only currently have five shortcuts set up there, but you can set up way more than that, plus a whole second row of them, if you want.
Edit: added screenshot
Edit 2: typo
Elixir - system information app with highly configurable widgets for your home screen and/or notification bar.
It's a pretty old app, but one of my favorite apps ever, easily. I personally use it solely for custom notification bar shortcuts, but it does so much more. Check it out!
Edit: link
try a process monitor like this, maybe indicates which process/app drains cpu/ram.
also, do you use fakegps(appninjas) added in Dev Options-Mock App- and with all options in Settings disabled ?
Oh. There are a bunch of general sensor reader apps; Elixir 2, which has a bunch of other utilities is my choice there. I've been using Light Meter for flashlight stuff, and I'm working on something better.
That's why I use Elixir 2, which can show signal strength as a percentage. On my phone basically anything over 35% is 5 bars. Right now I'm bouncing between 1 & 2 bars, giving me a signal strength percentage between 19 & 22%. Only time it ever goes over 50% is when there's a tower within eyeshot.
Have you run any diagnostics or hardware scans? Try using Elixir 2 (or another app that can detect hardware) to scan the available hardware. It may be that the camera has become disconnected from the mainboard.
What makes me suspect that the hardware has become disconnected: The Nexus 9's camera is wedged pretty tightly into the rear plastic housing. In the iFixit teardown, the technician pulled off the camera by accident. Reconnecting the camera would require removing the mainboard which is a lot of work. Whoever sold it to you might have done their own teardown.
From a 1.8A Blackberry charger, 1.8A power bank or 2.1A car charger using a good cable, a bit over 2 hours from dead to full. The factory charger takes longer. It also takes longer if it's running something power-hungry like GPS navigation.
A likely problem is that your combination of charger and USB cable is being detected as a data-capable connection and the phone is slowing down the charge rate so as to not disrupt data communication. System monitoring apps like Elixir2 can tell you whether it's in USB mode or AC mode and the rate at which it's charging or draining the battery. Around 1000ma is the full-speed charging rate, so if it's in AC mode and you're not getting that, the charger or cable is inadequate.
If it's in USB mode, you can get it in to AC mode using a charge-only cable, a different adapter or a third-party kernel and configuration tool that lets you select in software. FKU supports this, as does Cyanogenmod.
Try an app such as Elixir which would allow you to view the raw compass (magnetic field sensor) data:
https://play.google.com/store/apps/details?id=com.bartat.android.elixir
Elixir, last updated on March 25, 2018
It's late here, so I will have to try tomorrow, but I think I may have found a solution on android stackexchange The poster gives the three options below, and also shows command line option.
Many apps available from Play Store show the install and update time of the installed apps. I've tested three of them and have given instructions to use them appropriately.
After installing and launching it, go into Applications → tap on your app's entry → View Details.
Install and launch the app → tap your app's entry.
Install and launch the app → from the left sidebar select Applications → User apps → tap on your app's entry.
Download elixir and see if your sensors are dead or faulty :
https://play.google.com/store/apps/details?id=com.bartat.android.elixir
Elixir 2 along with Widgets and System addins.
crazy customizable widget creator and system monitor.
Download this app to test your sensors.