35 countries. It's mentioned on the Aio site's Plans page. which also has a link to a popup listing the supported countries which include Canada, Mexico, India and the UK. The $50 and $60 plans both offer unlimited domestic talk and messaging. The $50 plan includes 2.5GB of high speed data and the $60 plan ups the hi-speed data allowance to 5GB.
Free international text messaging is common with Sprint and T-Mobile MVNOs but not AT&T ones. AT&T seems to limit affordable international messaging to in-house products like GoPhone, which has long included no-extra cost international messaging on most plans Prior to this week's change international messaging on Aio was only available with the $15/month Aio Passport add-on.
Adding free international texting is the latest in a number of tweaks that AT&T has made to Aio's plan and feature offerings in advance of re-branding the service as the "New Cricket". Other recent changes at Aio have included auto pay and multi-line discounts, lower plan prices and more data. I expect to see AT&T use the Cricket brand to compete aggressively with T-Mobile's MetroPCS and Sprint's Boost Mobile using Cricket's extensive dealer network along with feature differentiators like international messaging, which both Boost and MetroPCS currently charge extra for.
Source: Aio via HowardForums, Image: Facebook