I first used Status.im when somebody told me about it at devcon4 and I think it is really great, it looks good and it is fairly easy to navigate.
Not knowing the inner technology I assumed my messages would be stored on some server persistently, but I haven’t tried it and I don’t have 2 mobile phones.
But what is persistent and what is not? From this thread (Operation Eat the Cluster: A Proposal), it sounds like something may even not persist more than 24 hours.
How would I store my messages for years reliably?