Secure Messaging App Over Wifi Network

[music_man185]

I do not have any signal where I work. So to save battery, I turn on airplane mode and use my company's wifi. I use hangouts to communicate during the day. Lately, I've become concerned that my conversations may not be safe and secure. I want an app that keeps my conversations safe from prying eyes. I found a site that rates the security of each messaging app (https://www.eff.org/secure-messaging-scorecard#changelog). It says that hangouts encrypts in transit. Is this what I need? It also says that "we are not requiring encryption of data that is transmitted on a company network, though that is ideal. We do not require that metadata (such as user names or addresses) is encrypted." If hangouts is safe, I will continue to use it. But if it is not, what should I look for in a messaging app to know that it is safe across other wifi networks?