JDownloader is not available for Opera but there are some alternatives with similar functionality. The best Opera alternative is DownThemAll, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 100 alternatives to JDownloader and six of them are available for Opera so hopefully you can find a suitable replacement. Other interesting Opera alternatives to JDownloader are Bulk Media Downloader (Free, Open Source), Turbo Download Manager (Free, Open Source), Ant Download Manager (Freemium) and MyJDownloader (Free, Open Source).
Bulk Media Downloader grabs and downloads all sort of media resources in bulk. You can filter different types to prevent cluttering the grabber window. It also has a pause button to stop appending more resources.
Hiposave - download photos/videos from Instagram. Description: The Hiposave online service allows you to download photos and videos from any open profiles on Instagram without loss of quality to your mobile device or PC, using Safari and other browsers.