True there are some verifications required and probably some good amount of money but scammers who are so determined can do that. It probably shows you that they could be having more than enough money, probably scammed from elsewhere. Think about scammers making an investment

Secondly, sparrow wallets left a void in the mobile phone software space. They only have the app for the PC operating systems, thus the scammers would easily create mobile versions and publish them over there without quickly getting noticed... By the time the app is pinpointed, it's already too late. I don't think it would be easy for them (scammers) if there were official sparrow wallet apps published in those app stores.
Scammers can be very determined and have much of money which they might use to create more advanced scams like fake apps. This makes it difficult to stay safe. Also because there is not official Sparrow Wallet mobile app scammers can easily create fake ones. If real app existed it would be much easier to spot fakes. Without one scammer app can look real to people who do not know any better.