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Free app offers cryptocurrency to people who brush, floss

by BOB AND JOY SCHWABACH | July 28, 2018 at 2:07 a.m.

It's a brave new world for dental patients: There's a financial incentive to brush.

We just earned 226 Dentacoins, a form of cryptocurrency, from brushing three times. We looked up their value and at the time of writing, they totaled 8.4 cents. There are a dozen exchanges where we could sell our cryptocurrency to get our 8.4 cents, but the Dentacoin app says we must wait until we've accumulated more. Nuts. The brief spike in January when that amount of Dentacoin would have been worth $1.30 is gone, fallen into a cavity.

Dentacare Health Training is a free app for Android or iPhone. It aims to make you a better brusher and flosser by guiding you through a timed session. A small amount of Dentacoins are awarded for each session.

The fun part is the music and the motivation. The app often calls us "Darling," or "Sunshine." It praises us when we've brushed, flossed and rinsed. However, setup is not for the non-techy. If you want to sell your Dentacoin, you must first have an "Ethereum wallet," and give the app that address. Addresses are OK to share because they're only for receiving money. We set up our Ethereum account on

So far, 38 dental clinics in 14 countries are using Dentacoins. The app itself has 23,000 users so far.


We still like a landline, and we read recently that 40 percent of phone owners do as well. The fact is, handsets are more comfortable and easier to handle than cellphones, and they have a big dial pad and a louder speaker phone.

We were Vonage customers for years, which gave us a relatively cheap Wi-Fi phone service that works with a landline. Then we switched to Magic Jack.

Why did we do this? It's cheap. Magic Jack is only $39 a year. But our phone was dead about 90 percent of the time whenever we wanted to call out. So we switched back to Vonage and were assured that we could have our old number back. After all, we'd had that number with Vonage for eight years.

Then came the bad news. Magic Jack said that if we canceled, we'd lose that number. So now we have four numbers: Two cellphone numbers, our old landline number that transfers automatically to a cellphone, and a new phone number from Vonage. This gives telemarketers four times as many chances to reach us with their urgent messages. Two landline numbers means two payments, $39 a year for Magic Jack and about $22 a month for Vonage. Egads, as the bard might say.


Joy turned to a new book on cryptocurrency with a leery eye, having lost a little money in bitcoin. Even so, she believes that some form of "e-cash" will someday take off. It's certainly very popular in science fiction stories.

The Truth Machine: The Blockchain and the Future of Everything, by Michael Casey and Paul Vigna, tells you why it's likely to happen, though Bob remains skeptical. It's his job. Casey and Vigna's central point is that a digital payments system allows users to cut out the intermediary and make records unhackable. This is crucial in countries where corruption is common. It can speed up settlements between buyers and sellers all over the globe, and open new markets like the market for your personal data, something offered already by a company called The Netherlands, more than any other country we've read about, seems to be forging ahead as cryptocurrency pioneers. That's because they often go Dutch. (Sorry about that.)

For instance, there's a Virtual Power Plant project in Amsterdam. The battery packs owned by homeowners are connected to microgrids that keep everyone topped up; there's no need for a power company. Every transaction is encrypted and secured by the blockchain, a continuous digital ledger.

We came across The Truth Machine because the head of Sotheby's, the auction house, said that a smart millennial recommended it to him. The book has more technical detail than we'd like but makes some interesting points. The authors say that what makes the blockchain so revolutionary is the invention of "triple-entry bookkeeping." You take the double-entry system which made the Renaissance so profitable and add a third component, an open ledger secured by code. It involves a signed receipt for every transaction and a time and date stamp. It is an excellent way to ward off fraud.


Every day we see a new story about Facebook, Google or someone else profiting from your data. How about you profiting from it?

We just installed Datum, a free app for Android, iPhone and computers, from It lets you sell your own info. First, we gave advertisers permission to send us one email per month, then we allowed our background location data to be collected for a month. Heck, if we go to Timbuktu, we don't care who knows it.

Our email could be worth up to 100 data access tokens -- another cryptocurrency -- per month, or $1.55 per current exchange rates, according to the app. We tried out their data calculator, at, and found out that a person willing to share his full profile, location and health data with any firm online is worth about $2,000 to companies.

Bob and Joy Schwabach can be reached by email at and

Business on 07/28/2018

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