Announcing my latest pet project, Helm Wallet.

I believe there’s a huge gap between the ease of use of Wallet of Satoshi and the self-custody of Phoenix. To minimize this gap, I created a new web app, a wallet that has the self-custody of Phoenix and is easy to use as WoS.

Helm is a Liquid wallet that uses Boltz submarine swaps to disguise itself …

The problem:

Imagine you are in Portugal, you want to go surfing, but you don't know where the best waves are.

What do you do?

Well, you open your surf guide, see what surf spots are near enough, search for a beachcam on that spot, and after some thorough evaluation, you finally decide where to go. Now it's time to search for the spot on G…

Every now and then people ask me for iOS versions of my mobile apps.

I don't build them, due to the following text in the Apple Developer Agreement:

11. Apple Independent Development. Nothing in this Agreement will impair Apple’s right to develop, acquire, license, market, promote or distribute products, software or technologies that perform the…

Today I'm proud to announce http://hatitude.pt, the place where you help an athlete every time you buy men's underwear. The idea was presented to me by Hugo. I loved it, and so I decided to help him by developing the website.

The problem

As you might know, only a couple of sports - like football - have financial help and support. There are thousa…

What a clever idea. The possibilites are endless. Well played Nintendo.

Bitcoin Cash double spends

Double spend is when a set of coins is spent in more than one transaction. This can happen for various reasons, but one of the reasons is fraud attempts.

Bitcoin Cash accepts 0-conf payments, which I consider insecure by default. But I would like to have some data to support this, so I went looking.

Since …

How can I buy Bitcoin?
Generate a password, and then pay someone to send bitcoins to that password.

A password?! That's it?
Yep, that's it.

What do you mean with "send to a password"?
It means those bitcoins now belong to the owner of that password.

What if someone finds my password?
Then he will be able to spend your bitcoins.

H…

Do you know which Bitcoin constant is this?

26,959,535,291,011,309,493,156,476,344,723,991,336,010,898,738,574,164,086,137,773,096,960

Maybe in its hexadecimal format?

0x00000000FFFF0000000000000000000000000000000000000000000000000000

Yes, it’s the maximum target hash.

But what thus it means, and why this “weird” value?

Bitcoin’s protocol wants b…