(I'm referring to the Andrea's schildbach bitcoin wallet app)...
I didn´t knew this wallet.
I just made a small research about it, quite interesting to know it was the first bitcoin mobile wallet ever. I will download it later to check it out.
The Schildbach Bitcoin Wallet (simply Bitcoin Wallet on the Android store) was the first Bitcoin wallet for mobile and it has over a million downloads. It was created in order to simplify Bitcoin transactions for anyone who wants to invest in the cryptocurrency and has many useful features that its users appreciate. Many new mobile wallets were developed based on its open-source code.
https://www.bitrates.com/wallet/schildbach-bitcoin-walletNowadays we have some good options for native segwit wallets for android.
I like to use Samurai and Coinomi (which i know is not open source, but I really like it).