This is one of the first apps you’ll come across if you’re looking to hide photos on Android. You can fire up the app and then choose pictures and videos to add to your secure vault, or you can select share on the photo or video itself and choose Vaulty from the list. Either way the result is that your photos and videos are hidden in a private gallery which can be password- or PIN-protected. This means they are not accessible from file managers either. You can also view, search, zoom, share, filter, and rename photos from within the app, and it’s easy to filter videos and select multiple files.
Of course the presence of the Vaulty app gives away the fact that you have something to hide, even if the nosy person searching your phone can’t get to it. If you want an extra level of stealth then you might consider splashing out $4.99 for Vaulty Stocks. It does exactly the same thing but stores everything behind a fake stocks lookup app.