Folder-Lock-For-Android

Folder Lock for Android allows you to password-protect your personal files, photos, videos, documents, contacts and every other sort of data. Moreover, you can view your photos and watch your secured videos within the app’s secure interface. You can write secure notes and record voice secretly. You have the liberty to import files from the SD card or download it directly into the app using its built-in browser. If you want to transfer your files from your PC or Mac, you can transfer them easily via WiFi using the PC/Mac feature. It has other features like panic switch, hack attempts monitoring, stealth mode and others that can beef up your security.
https://play.google.com/store/apps/details?id=com.newsoftwares.folderlock_v1