The Circle app is well designed and easy to use with a whole host of features enabling easy money transfer and syncing with your traditional bank accounts. Circle fully insures your cryptocurrencies deposits through Lloyds of London underwriters.
Pros
Commission-free cryptocurrency investments, Multiple coins including Bitcoin (BTC), Ethereum (ETH), Litecoin (LTC) and more. Instant buys from your bank account - $1 minimums make it easy to track your performance and learn as you go - Covering your assets with offline storage, 256-bit encryption, two-step verification - Screen locking by using TouchID, FaceID or a Fingerprint
2 Factor Authentication
Cons
Hierarchical Deterministic - Open Source - Multi-Signature