Seeking a roaming free sim during international Tour

"Roaming free" means you can't use it in any other country. I don't think you mean this.
You need to say which countries you are visiting. A SIM card or phone brought in one EU country will allow (relatively) cheap roaming in other EU countries. The EU commission puts limits on the surcharges for roaming.
Outside the EU there are no limits, and "international roaming" (using a SIM card from one country in another country) can be expensive.

you also need to say, please, what type of phone you have and your carrier/provider.

I also am traveling to southern Spain and would like info on a "nano-Sim" for my IPHONE 5.

Another poster "Eileen" sent me this answer on a PM.

" . . . This will be a lot of info that will probably be as clear as mud LOL! OK - first of all, I'll include the link to EuroBuzz (http://www.eurobuzz.com) in case you need it. Also, this (if the link worked!) might be useful, too - under the FAQ this is Q#4 concerning phone calls outside of Europe. If you use their SIM to make a call within the USA (but NOT using their Europe-only dual-band phones!) the rates are shown in the link above. You will receive a European phone number (from the UK) AND a USA phone number. Because this phone is meant primarily as a European phone, the rates are higher for calling outside of Europe...but unless you're calling just to talk, it's not crazy expensive. . . . It's the same flat rate of $0.79/minute for you to call (the USA). . . . If others in your traveling group also use EuroBuzz SIMs, outgoing texts are $0.79, and incoming texts are free. I highly recommend their phones, too - I would be anxious about being out and about with my $$$$ (edited)// + or - ;-) // iPhone with ALL of my contact info, photos, etc., on it. Their phones are lightweight, have good battery life, and I didn't have to worry about damaging my iPhone SIM while toting it around Europe.
My package arrived within a few days. You'll then have your European AND USA phone numbers to give to whomever you please. These numbers never change. If you also order their phone, you insert the battery and charge your phone at home (using the North American adapters included), but if you purchase their phone you can't actually use the phone until arriving in Europe (since they are dual-band phones that only work in Europe and other countries except the USA). This SIM will never need to be 'topped up', or otherwise attended to - you'll keep the same phone numbers, too! Just charge it when you leave on your next trip. Nothing else to do! If you never use the SIM, you never pay more than your original order amount. It's a pay-as-you-go, post-paid type arrangement. This is perfect for sporadic travelers. In fact, after having not used the phones for over two years, EuroBuzz sent me an email to let me know that the credit card on file was nearing its expiration date! All I had to do was send them the new exp. date. I'm all set for another 3 or so years. After our return home, we received the correct charges on out credit card. Everything worked as advertised. Yea!
Please let me know if you need clarification! Their current deal of two phones and SIMs for $39 is great; S&H is about $10, I believe. Or, you could choose a $29 phone and SIM, plus just a SIM if you wanted to."

(Colette here again) . . . My concern was being able to be reached from the States should there be an emergency w/an elderly family member. Eileen had explained EuroBuzz better than some of the other comments I read.

I can put my cellphone on vacation hold while I am gone.

Hope this helps.

My 2-cents worth.

Check out T-Mobile. Last year I got a simm card for my iPhone5 and used it all over Spain and Portugal. You have a US tel# that allows anyone in the States to call you at no charge. Worked great in both countries; just like home. I got their $60 a month plan and could have used the $50 plan for my 2 week trip. Calls in country are $.20 minute, unlimited data and text. BUT YOU MUST HAVE AN UNLOCKED PHONE!