Platform 16.0.1 (Apr 11, 2019). Please donate.
400+ real apps, New: QOwnNotes (Apr 10, 2019)
Over 810 million app downloads
Any idea of online sites I can do this
Although this site caters to software for personal computers, your best bet would be Google drive or a similar like service, Dropbox etc. There are hardware type backups like wifi enabled HDDs and flashdrives, but I'm not familiar with those.