Navigate to your Instagram Photos folder in the Dropbox app. To download a photo, tap the small download icon in the bottom-right corner of the photo, then tap Save Image.
With recent versions of Android, you don't have to download the photos to your device to use them in Instagram.
If you have an older version of Android, though, you'll have to download the files to your phone, as with iOS. This is also the case if you're using BlueStacks to emulate an Android device on your PC.
Navigate to your Instagram Photos folder and find the photos you want to use. Tap and hold on the photo's name, then select Export from the menu that opens up. From there, choose to save the picture to the SD card.
Save the photo in your device's Pictures folder--this will make it available in the Gallery. You can use this same procedure to export an entire folder at once.
Step Three: Post to Instagram
Now you're ready to use Instagram to edit and post your photo. This process is nearly identical in both the Android and iPhone Instagram apps.
To begin, open Instagram and tap the blue 'shutter' button located directly in the center of the bottom bar. To the left of that button, you'll see a button to open a saved image.
Selecting photos in iOS
In iOS, you access saved images via an icon showing a thumbnail of the most recent image in your camera roll. Tap it, and photos will appear at the bottom of the screen, including those we transferred over from Dropbox.
Tap the photo you want to use, crop it (if necessary), and tap Next.
Selecting photos in Android
In Android, tap the saved-image button, which looks like a tic-tac-toe grid of nine squares.
If you have a recent version of Android, you'll be presented with an option to choose where to look for your photos. You should see an option to use Dropbox.
If you don't see an option to choose the source of the photos (or you don't see the Dropbox icon), download the photos manually per the instructions above.
Tap the Dropbox icon, navigate to your Instagram Photos folder and select the photo you want to share.
In older versions of Android (or if you downloaded the photos to your phone manually), look for the photos in the Gallery.
After you select your photo, you can use the standard suite of Instagram editing tools and filters. Finally, post to your feed and prepare for a shower of Likes and admiring comments.
Have fun, and happy shooting!
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