I installed the OwnCloud app on an Android 6.0.1 device, but realised that it doesn't work for files over about 2-5MB. The problem is that (a) the app will cancel all pending downloads if it's terminated and never retry them, and (b) it gets terminated if the phone goes to sleep or you switch apps. So literally the only way to have my videos upload is if I sit there and poke the screen while the OC app runs in the foreground. Even then it's pretty flaky, and retrying uploads doesn't really help, it just starts the whole cycle again.
I tried FolderSync, but it doesn't do instant upload, just very coarse grained scheduling.
Is there an Android app that will reliably upload files bigger than a few MB and is good for instant uploading of camera media?