What is Picture Manager?
Some manufactures like HTC and Sony (probably some more) save pictures taken with an incremented number in the filename, instead with a timestamp like other manufactures do.
When you factory reset your device, buy a new device or clean flash a custom rom, the camera picture counter gets reset and starts with e.g. IMAG_00001 again.
This can be an issue once you backup your files to a harddrive on your PC, because you will have duplicate filenames, although the pictures are actually different.
Picture Manager solves this problem by renaming your taken pictures with a timestamp format that you can select or even define yourself.
You can either start a batch process before you backup your pictures to your HDD, or automatically let Picture Manager rename your files in the background.
Another nice feature Picture Manager offers is that you can let it organize your taken pictures into folders that are named by the year, month and even day.
That will help you to quickly find your pictures again and brings some organization into you pictures.
You have to be on at least Android 5.0 Lollipop
How does it work
Picture Manager relies on the EXIF Metadata that is stored into each picture. The EXIF Metadata contains a lot of information, the one Picture Manager needs is the date the picture was taken.
With that information Picture Manager can reliably rename and organize your pictures.
Picture Manager comes with a Tasker Action Plugin. That means that you can start a batch process on different events, like time, when usb gets connected etc.
If you want to use the custom format, background service or the Tasker plugin you need to upgrade to the premium version.
To upgrade you can use an in app purchase. Or you paypal me and I mail you a premium code. That way google doesn't get 30% of the income.