I tried to find that Chivo Bitcoin wallet that looks like a mobile app but I couldn't find it Google store, maybe because it is available only for citizens of El Salvador
or maybe because they will officially release new Bitcoin law and app in September of this year.
One more thing I noticed is that you must register with your phone number and facial recognition or kyc verification through the call center for creating new account, and I think this is all based on strike.me application.
I am not sure if this app is going to be open source, but it is good that people have freedom to use any wallet they want, and open source is always a better choice.
I think this wallet will be disponible only for salvadorans citizens because it won't have transactions' fees or exchange's taxes between dollar and bitcoin. If it becomes disponible for any person in the world, many traders will want to migrate to Chivo Wallet and the costs will be too high for El Salvador's government to maintain, as the government is going to pay transactions and operational costs of this new wallet, since there isn't free lunch...