The best thing i like about blue wallet and started using it recently is the read only wallet, where I can watch my bitcoin balance in my wallet on my android phone and feel safe even if my android phone is lost no one can get access to my coins.
Yeah, that's what a watch-only wallet is for. Your wallet doesn't have private keys or a seed imported into the software. Therefore, it can't sign and send transactions. But you can import specific addresses or the master public key (xpub) to monitor the balances of all the addresses in your wallet. And yeah, if someone steals your phone, they don't get the signing keys to your coins. However, you lose your privacy because they can see everything you have in that wallet and in which addresses.