This is a mini battery monitor for your phone. It monitor the battery level in %, temperature usage in °C or °F, and voltage. It will always stay in the corner of your phone's screen. You can set the indicator to any corners of the screen, customize the color and transparency of the indicator. Advanced notification support battery usage chart for 12 hours.

Pro version support auto-hide panel and other advanced features, and it is ad-free. Free trial:
https://market.android.com/details?id=info.kfsoft.android.BatteryMonitor

Update Log:
1.0.84 Xiaomi fix (小米、紅米)
1.0.80
* Fix for Nexus 5
* Update Icon
* Minor Bug fix
1.0.77 Enforce READ_EXTERNAL_STORAGE permission for Kitkat (Read SD card fonts), minor fixes (4.4+)
1.0.75 Optimization (Battery)
1.0.73 Bug fix (color)
1.0.71 Start on boot
1.0.67 Notification fix (4.3+)
1.0.65 Manual input to custom location xy
1.0.64 Text alignment, +sign when charging
1.0.63 Exclusion apps list (require GET_TASKS PERMISSION)
1.0.61 Custom Location
1.0.60 Voltage reading
1.0.59 Shadow and 0 transparency
1.0.58 Color picker bug fix
1.0.57 Touch Through
1.0.40-50 Custom height / width / font size / color / font

Recent changes:
★★★ Screen overlay detected → Go to "Auto-Hide" section, turn ON "Permissions Screen" ★★★

1.0.119-121
* Fix for android 8.1

1.0.117
* Bug fix

1.0.115-116
* Fix for android O

1.0.113
* Fix for android 7

1.0.111
* Widescreen support

1.0.109
* New Icon
* Bug fix for android 5,6,7

1.0.105
* Force close fix for samsung rom
* Add "Hide in permissions screen" option to avoid "screen overlay detected"

1.0.103 Stability fix for 5.1.1
1.0.99 Stability fix