I used RClone to sync to B2. They've got an iPhone app that you can download to browse + download from the bucket, else the website itself.
There might be further reasons for it, but I mostly use it as an offsite backup that my wife could upload to -- so usability was a plus -- but not worth that kind of premium.
There might be further reasons for it, but I mostly use it as an offsite backup that my wife could upload to -- so usability was a plus -- but not worth that kind of premium.