edit: grammar
Whatsapp however regularly loses its connection on Wifi (even when on battery, and wifi powersaving is disabled), and after 6 hours I see "oh, 20 new messages"...
Problem of scale is that neither of the three (or, actually two) companies has a public bug tracker where one could report bugs and see if anything happened with it. You basically feel like you're interacting with a fucking black box.
You know what rarely crashes for me? m.facebook.com on a web browser.
Facebook will never get installed on any device I own. Ever.
A relevant article from a Mozilla developer, James Long: http://jlongster.com/Radical-Statements-about-the-Mobile-Web...
I know that exist Tinfoil if you concerned about privacy: