Soon you can buy your OnePlus 6, but you can experience some of its apps today thanks to XDA user erayrafet, who ripped off some OxygenOS apps like Weather and this gallery app. While Google Photos is a great service, this gallery app should be your go-to app for locally stored photos.
The main advantage of the OnePlus Gallery app is that it is lightweight. It is easy to use and fully in line with the theme of OnePlus software in general: simplicity. It does not try to reinvent the wheel, but what it does does it effectively. Unless you're used to slogging apps, you can be intimidated by this whole process. But do not worry, because everything is described here.
: Enable Unknown Sources / Install Unknown Apps
Before you can do anything else, make sure your smartphone is set up to load apps. If you're using Android Nougat or earlier versions, unknown sources allow you to install apps on your phone that you did not download from Google Play.
If your phone runs Android Oreo or later, you need to do this Give your browser permission to install unknown apps. You can either do this now or while trying to install the OnePlus Gallery app. If you're not fussy, it's easier if you try to install the app because you just tap Settings, then tick a box and then press Install.
Step 2: Install the OnePlus Gallery App
Next you will get the OnePlus Gallery APK via the following link. When prompted, tap Download. If you have trouble downloading, you may need to long press the link and manually select "Download link". After you download it, the file appears in your notification color.
Your phone will then confirm that you want to install the app. Tap on "Install" and then on "Open" when your phone has finished the installation.
If you've decided to allow your browser to install Unknown Apps on your Oreo phone (or higher), you can find information here. Touch "Settings" when prompted. Simply turn on the switch on the next screen, tap the back button, and then tap Install.