Platform 15.0.2 (May 17, 2018). Please donate.
400+ real apps, New: LibreOffice Legacy 5.4 (Aug 10, 2018)
Over 990 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.