I like that it's encrypted so if someone tries to hack into my phone they can't access anything without me knowing about their intrusion first! It also has an option for two way voice calls which was great when we were in different states but not always possible with other apps/services out there now (like Google Duo).
The app itself isn’t very intuitive or user friendly - you have no idea what all of your features are until after downloading them from iTunes even though some options might be right at hand under ‘settings'. If anyone wants something simple yet effective then this would work well as long term solution because once set up nothing else works quite how one needs except maybe Whatsapp? We used silent circle mainly just text messaging between us both while overseas where our service providers weren't reliable enough sometimes due privacy concerns etc..