3C Battery Monitor Pro to unlock key

Starting with 3C Battery Monitor v4.0, the pro APK is an unlock key to the main app version (3C Battery Monitor).

Clean install

Migration

Please make sure to install the main app as well if you have an existing installation of the pro version.
Open pro app from app drawer. It will confirm all data have been exported.
Open main app (free version), app settings, help and support and tap import app settings. App will restart.
Things that needs manual handling:

Widgets: Add the same widgets you used and load their settings. Graphics widgets will restore historical data as well.
Permissions and special permissions: None will be granted, which may impact various features of the app, most will be requested when opening app's various features.
BATTERY_STATS can no longer be granted (Play Store requirements), so please install 3C Battery Stats from here if you where using that permission, and grant it the needed permission with root or ADB as described here.

You'll get better and faster support.
A few times per month a user complains that he bought the pro version but still have ads, and no extra features.
When providing updated APK to test bug fixes, I'll only have to provide the same APK.
Building/testing/publishing 2 apps which are actually identical is time-consuming, and I have to maintain 3 other apps with the same model.
Paid versions suffers from excessive wake-ups (monitoring with high unlocked refresh rates), this will disappear with pro being an unlock key.
In short, everything is much simpler and faster.