Preferred "texting/VoIP" apps?

Read some threads on this topic, but nothing too recent, so I thought i would pose the question again. As wifi packages are becoming more affordable onboard, what is your favorite app for device-to-device texting, VoIP phone calls, etc. I am somewhat familiar with Viber, WhatsApp and Kik, but haven't used any of these on a cruise. Looking for advice, tips, and any other conversation on the subject.

My next cruise is on Majesty, so anyone with experience using one of these apps on Majesty's (slower speed) wifi would be especially relevant to me.

Thanks all!

I know people who were successfully using WhatsApp for texting on Liberty this past March. Liberty still had the slow internet at that point.

If you purchase the onboard wifi package you could use an app called Talkatone for texting and phone calls. If you are using an Iphone you can use IMessage for texting. Either way make sure your cellular data is turned off. Have s great cruise.

My favorite VoIP app is Vonage, but I have yet to meet a single ship's WiFi with fast & good enough quality to handle any real voice conversations.