Most cost effective way for phone contact to US from Europe

I liked the ease ( and no cost!) of WhatsApp, assuming your contacts all have smart phones. You would need to be sure that those you ) want to contact also download it to their phone, if they don't already have it.) Free WiFi was really prevalent, for example, checking maps for next destination while in a museum or cafe. AT&T has a travel plan for calls/data?

Skype or Facebook chat works well as does What’sApp.

The Google Hangouts app is your best option, because you can call even US landlines or any US phone number for free. The other person doesn't need the app - just call them using the phone number in your contacts. (You may need to add a +1 to the front of the number when calling from Europe.) It's nice to be able to call your airline or bank's regular landline number and not worry about an expensive call if you get put on hold - and they probably won't be on WhatsApp or Facetime. And you can make as many non-emergency calls home as you want for free.

Google Hangouts, like the others, needs either WiFi or mobile data to work. In my experience it uses about 2MB/minute, so probably best to make calls while on WiFi unless you have a ton of data you can use.

If you want people to call you too (incoming calls in Hangouts), all you need to do is sign up for a free Google Voice number. Then go into Hangouts and enable incoming calls. People from the US can contact you by calling your US Google number. One thing: you use your AT&T number to sign up for Google Voice, but after you sign up, turn forwarding "OFF" in Google Voice; otherwise, it will ring your AT&T number too - and you probably won't want that in Europe.

If you just want to make free outgoing calls, don't worry about Google Voice - just install Hangouts, very easy. Try it at home first before you leave for Europe.

My answer above was to your thread title, "Most cost effective way for phone contact to US from Europe" - but WhatsApp is popular in Europe for local calls. You can make calls to non-US numbers with Hangouts but like Skype it costs a few cents per minute. Only calls to US numbers are free.

When I was in Sicily last year I used my advanced calling on my Android phone (Galaxy S8). It works wherever you have a Wifi connection. Not sure what it is called on an Apple but it is there. No charge. Funny story is that my sister called me in the middle of the night, not knowing I was out of the country and wondered why I was a bit concerned getting a phone call at 2 am local time, thinking there was something very wrong at home besides her wanting to ask a question about something.

Have also used What's App but that does require some prep before leaving so that everyone is on the app.

I also get international service from Verizon for $25.00 for the month which I keep for the possibility of needing to call and not being in range of a Wifi. Then there is only a $10 charge for the day. Helped when I needed to meet someone in Rome and had to arrange a place that day.

Facebook messenger has worked well for me. You can either make a call or have a video chat and it's free. Everyone needs to have a good internet connection.

Look at the ATT monthly international monthly passport plan ($60) to see if it will meet your needs and budget. It has worked very well for me. Unlimited texts, 1 GB data, US phone calls .33 a minute. Your phone number remains the same.

I used ATT international plan. Unlimited data and calls. Last year it was $10 a day. But you are only charged for the days you use it. We used it for calla and GPS when we changed areas of the country. So made calls home on the days we needed it for GPS.

I used ATT international plan. Unlimited data and calls. Last year it was $10 a day. But you are only charged for the days you use it. We used it for calla and GPS when we changed areas of the country. So made calls home on the days we needed it for GPS.

You don't need mobile data for driving GPS if you use "offline" mode for the mapping app (like Goggle Maps and other apps have).

You can also make free phone calls home to the US (even to landlines, so the other person doesn't need an app) with Google Hangouts while on WiFi.

But mobile data is essential for walking/public transit navigation - at least, it is to me.