Trust Browser is open source, which make the product transparent by default.
In terms of security, mobile OS was designed to have closed ecosystem and make it secure by default. Trust uses best practices for storing private keys on the phone and it’s encrypted with 256 bit password.
Best way to read reviews: just go to App Store/Google Play and press on reviews, there is thousands of people leaving their feedback and excitement!
Source code is available on GitHub: https://github.com/TrustWallet/trust-wallet-ios
Security audit: https://trustwalletapp.com/assets/trust-wallet-exec-checklist.pdf
Only download and install from the official metamask.io . Subsequent to that, it'll be loaded in your browser going forward. Then if you want to be extra cautious, you can then verify each time you're entering the exchange that the MetaMask address is the same as originally given you. Most people don't feel a need to do this.
The address you're given is your wallet address, not an exchange address. Besides, you can import any wallet you like into MetaMask and work with it instead of the one MetaMask gives you.