Pretty sure you open the app, go to File List > Downloaded Videos. The files should be listed there. You can then click on the three vertical dots and 'export' it to your iphone camera library for uploading, sharing, etc.
You have to download the file, which will move it from the memory card to the apps internal memory.
Then you have to click the dots to share the file, which should allow you to save to albums.
Pretty sure you open the app, go to File List > Downloaded Videos. The files should be listed there. You can then click on the three vertical dots and 'export' it to your iphone camera library for uploading, sharing, etc.