Croc is described as 'Enables secure peer-to-peer file transfers across platforms with encrypted code phrase authentication, resuming interrupted transfers without external storage' and is a large file transfer service in the file sharing category. There are more than 100 alternatives to Croc for a variety of platforms, including Web-based, Windows, Mac, Linux and Android apps. The best Croc alternative is LocalSend, which is both free and Open Source. Other great apps like Croc are Syncthing, KDE Connect, OnionShare and Send.