RE: Traveling as a couple for under $50 usd a day is POSSIBLE and 100% worth it. (Video)
Hey awesome!
But, you missed out on the practical parts... let me help you with that :)
Here's my secret recipe for travelling cheap
1. Lodging is usually the most unavoidably expensive part of travel in 2nd/3rd world countries. Start by optimizing here.

The booze served is excellent, but not for budget travelers. (The Royal Livingstone Hotel, Zambia)
Trains and buses are often dirt cheap, hotels not so much.
So, use Booking.com and Agoda for finding rooms.
Booking.com is the most reliable of the two, and it's the largest hotel site in the world with coverage seemingly everywhere. They are also reliably cheaper than the major hostel booking sites for booking hostels, based on my tests.
How to use Booking.com:
- You can use it to find the cheapest rooms in a city, but you can also search a whole country at a time! Either way, enter the place you want to search, your travel dates, and click search.
- Then, choose "sort by lowest price" and they will generally find you the cheapest lodging in an area -- at least, the cheapest that's available online.
(There's no need to set up an account, the "special deals" they offer to people with accounts are for more expensive hotels, not the rock bottom cheap stuff we want.)
Agoda is tricky because they don't show taxes until the end, but sometimes (e.g in Asian countries) they are a little cheaper.
2. Now, work on finding the cheapest ways to get from point A to point B
I usually like to start with Rome2Rio to get a feel for the different options. They will show you rough estimates of e.g train, bus, ferry, and airplane prices.
However, the prices will often be VERY different in practice so don't use this for budgeting.
For air travel, Skyscanner is pretty much the only way to fly for the budget traveler.
No, don't just use it like you would Expedia or whatever. Take advantage of their advanced features, like searching the whole month to find the cheapest day to travel on.
This can often save you several hundred dollars each way!
And if you really want to be extreme, Skyscanner will let you do "open ended" searches, so if you just want to "go somewhere" you can actually find the cheapest destination from whichever airport you are at.
One caveat: Skyscanner's search prices appear to be based on the results from people who previously booked on those dates, so for unpopular routes you may not find nearly as much information.
Pro tip: fly between major hubs
Here's a BIG secret... don't fly into minor airports if you can at all avoid it. It's usually DRAMATICALLY cheaper to fly into a major travel hub (like Bangkok) and then take a bus than it is to fly into somewhere small.
Why? Because there's more price competition on the popular routes.

This is not a major travel hub, there is only one flight and, while the food they serve is excellent, the departure is always delayed. (Namaste Air Nandoj restaurant, Nepal)
3. Live and travel like a local
Apps suck. Sorry, there you have it.
Anything that's listed online or in an app will tend to be more expensive than what the locals pay, just because it's available to the ENTIRE INTERNET.
So, you're much better off using the Internet stuff to book short term accommodations (so you don't end up sleeping on a park bench) and then do your longer term search once you get there.

Guaranteed not listed on booking.com, and far more comfortable than it looked
Ideally by, you know, talking to people.
Examples in practice
I was standing at a cigarette/cell phone kiosk the other day in a major Eastern European city and struck up a conversation with an Indian guy behind me. He turned out to be a student who was studying in the area.
I asked him, "do you know where I can get a cheap room here?"
"Right over there," he replied, pointing to a nice looking hotel.
"What?" I said, "That looks way too nice to be cheap."
"No," was his answer, "That's the cheapest place in town. You're not going to find a place that will beat their prices."
And indeed, when I walked in and asked, they had some of the best prices of a standard hotel type establishment in the city.
(Never mind I was already paying half that rate because of an obscure out of the way apartment I'd found on Booking.com.
But the location of my place was TERRIBLE, way outside the city on a 20 minute bus ride.
Whereas the place my student friend had pointed out was right in the middle of the city, about 30 seconds from the biggest public transit interchange point in town.)
Vienna
I applied a similar strategy when I was in Vienna a while back.
I had booked a hostel in advance, just in case... but then on arrival I struck up a conversation with a guy on the subway who mentioned he was booked into one right near by, so I followed him there.
It turned out to:
- be much better located, next to a huge train station with subway and bus connections
- have a spectacularly better vibe than the corporate mass market hostel I had reservations at,
and, - was a bit cheaper too!
And this is even more true in Asia
When I was in Nepal I used to laugh (inwardly) at the backpackers who got stressed at having to be up early in the morning the next day to catch their 7AM tourist bus.
Me, I didn't pay $15 or $30 or whatever it was that they were paying for a bus that ran once a day.
I paid $5 and took the "local bus"... which leaves just about every 15 minutes all day long. No reservations needed -- no reservations possible, in fact, you just show up!
Yes, they're cramped and full of locals (and sometimes local livestock, I once got to sit next to a few boxes of live freshly hatched chicks).
(And YES, you should bargain and don't accept "tourist prices" for things like this... it makes things harder for the locals if -- even if you can afford it -- you start throwing around cash and drive the prices up.)
But yeesh, you're travelling, you don't have to replicate "life back home" everywhere you go, learn to appreciate the local way of doing it!
Warning
Attempting this strategy in countries like India, Nepal, China, etc is NOT FOR BEGINNER TRAVELLERS. There is genuinely a huge cultural gap and it does take some adjustment.
Wow, this was way longer than I anticipated. Reposting/Crossposting it to my feed @traveladdict. Follow me for more crazy adventures.

Wow, what an information-filled comment! Thanks for sharing! I love your insight about flights, because that's just was I was looking for. Check out my recent post on traveling with a budget here: https://steemit.com/travel/@sarahjanele/how-to-visit-new-york-city-on-a-budget
You're welcome! I love your post, the idea of visiting NYC on a budget is... a little nuts. But glad to see you made it work without resorting to sleeping on park benches!
Pretty soon I'll post the next part of my zero-budget 1200km epic on my feed @traveladdict ... where I discovered who my host actually was... AND I finally finished writing up my trip to the "Goddess that grants all wishes" so I will post that soon too :)
We have a lot of similar interests Diego. Looking forward to seeing more from you.
I'm not Diego!