The best picture viewer QuickPic on Andriod – free and no ads, below is its features:

1. list tens of thousands of photos only takes less than 2 seconds and quickly identify your new download pictures without background service processes.
2. the best quality full screen browsing, slide show and support thumbnail preview.
3. specify folders or exclude folders, you can speed up scanning speed.
4. seamless experience: panning or switching, click or double click or double sliding scale the image.
5. turn, reduces, crop the picture, and you can set the best quality wallpapers on your Android phone.
6. rich picture file management features: sort, rename, new folder, move and copy photos.
7. it has been optimized for “big-screen HD flat-panel”
Advantages:
You can add a picture folder that you want to scan in the settings so that you can dramatically increase the scanning speed
Easily hide your private photos and videos, and you can set a password for protection purpose
Disadvantages:
If loading thumbnails is always too slow, maybe the database caching is damaged, the user must uninstall program, and then reinstall
If you forgotten your password, you also must reinstall QuickPic
Well while the video is playing, can only play standard videos and GIF animation
DigitByte Software for Windows, Mac, iPhone, iPad, iPod – free download