Honestly I like the design as it is modern, tho I really think that it might not be the good time to use your app now. As it is lacking of some features as I see there are some features that are currently in development. What is this exchange tab? Is it that we can connect through our API keys and thus have exchange on our wallet?

When you have more features put into the app, it might be good idea to try to list it on bitcoin.org website as there only opensource wallets are shown. I like the idea of open source wallets and this one looks great so far, keep up the good work!

So far I like the feature of pin as it is relatively easy to set up and when you have to use your wallet not hard to simply type few numbers. Though I think I've found bug on android app with PIN, it tells me when I enter it wrong that 5tries remain, when I enter incorrectly my PIN 5times then it states "1You reached maximum number of tries" and then it will count again starting from 5numbers, without locking me or something. Might be good idea to first ask user to backup their mnemonic before even letting them to do PIN lock because you want to focus on security of users funds. Maybe after these 5tries reset the wallet and put that user has to enter mnemonic again for security reasons.