cryptocurrency wallets based on mobile phones are the safest option for the short and medium term storage of cryptocurrencies.
I'm glad that someone, and take note of its big name in the industry, also agreed that mobile wallets can be considered as the safest way of storing crypto because that's what I've been thinking of all the way. Yeah! Some of you might disagree and still go in the favor of cold storage (it does) but when it comes to storing only few coins then not bad to use mobile wallets since they are more practical and convenient.
To save long-term cryptocurrencies, Samsung recommends creating multiple backups of the private key associated with the wallets.
The Smartphones producer commented that private keys should be stored offline to maximize their security, which means that they should not reside on a mobile phone or any device that connects to the internet regularly.
Though my private key is not in my hands. I know either why Coins.ph, the wallet I'm using, don't allow its users to have access on their own private keys. After a couple minutes of research, here's what I found:
https://support.coins.ph/hc/en-us/articles/360000071761-Can-I-have-access-to-my-private-keys- . Nevertheless, I don't worry about the security of my coins at all because I'm confident of my wallet's credibility and trustworthiness.
Ps: But still, much better if you hold your own private key.