I was able to do freelance iPhone development. If you're already good in C++, it will give you a leg up in learning objective-c.
Also, I could not agree more with the points about "working needs discipline." If you're staying in hostels, I would basically say forget it. I found it INCREDIBLY difficult to sit down and code when I was traveling around in hostels (like a tourist) and surrounded by fun people and things to do. In BA, I an apartment like the OP, which made getting work done a bit more tolerable (but still very challenging given the surroundings...)
We would advise not to do this while staying in hostels. Hostels are way too much fun, packed with people travelling and having fun. One needs a work environment to get work done.
Our trick was: arrive in a city/location and stay in in hostel/hotel for a few days. Meanwhile drive around/ask around/do couchsurfing to get to know places/check the local craigslist. And find yourself an apartment to live in.
Couchsurfing helped us a lot to get to know locals.
A co-office did the trick in Buenos Aires.
It costs money, but sitting in a coffeshops costs a lot of lattés too. :)
Also, I could not agree more with the points about "working needs discipline." If you're staying in hostels, I would basically say forget it. I found it INCREDIBLY difficult to sit down and code when I was traveling around in hostels (like a tourist) and surrounded by fun people and things to do. In BA, I an apartment like the OP, which made getting work done a bit more tolerable (but still very challenging given the surroundings...)