[ANN] ColdMonitor: a wallet for true HODLers (early preview)

[maxrann]

TL;DR: https://www.coldmonitor.com

Hola!

A few weeks ago, I started wondering what I could to help improve the often poor security practices of Bitcoin users and companies. I realized that people typically make tradeoffs between usability and security and wondered if I could help by making a good security practice, namely the use of cold wallets (wallets which are not stored on a networked device), more convenient to use.

http://i59.tinypic.com/mtmmgm.png

https://i.imgur.com/GFOTryil.png

People already use "watch only" wallets today through various means but I felt none of the solutions out there were focused on that specific use case.

So I started learning about Bitcoin's protocol and wrote a "watch only" wallet. It's still very much a work in progress but currently supports wallets made up of a list of addresses or an Electrum Master Public Key.

Here's a few features I have in mind for the future:

- Better UI (display the list of transactions in a smarter way, awareness of change addresses, etc.)
- Registration/login: ability to save wallets
- Receive email / SMS alerts when transactions occur
- API and web hooks which let users execute specific actions when specific transactions occur
- Ability to create new transactions in order to sign them offline
- Support for BIP32 HD wallets
- Some nice visualizations and graphs
- Your suggestions

Anyways, I'm posting this here to get some early feedback from the community and make sure I'm going in the right direction. Let me know your (constructive) criticism and keep in mind that this still very much a work in progress! (Please be nice, I've put a lot of sweat into this although it's still pretty basic)

Try it out! https://www.coldmonitor.com

[1715297599]

1715297599

[poordeveloper]

Do you plan on charging for the service? And specifically for SMS/email alerts?
Looks like an awesome idea. Best of luck!

[maxrann]

(Wow, a reply and a positive one at that!)

> Do you plan on charging for the service? And specifically for SMS/email alerts?

I haven't given much thought about that yet. I do plan to find a way to generate revenue eventually (at least to keep the lights on and keep my stomach full if I'm lucky) but I'm not sure what form it will take yet. I think I will probably go with a freemium type model: a free basic version and a paid version with additional features. Or have a free web app and sell a paid mobile app? Or make it free for wallets with less than X BTC and paid for wallets with more than X BTC? Or have everything free but charge for API usage? Just run on donations and hope that BTC will go to the moon?

Those are just some ideas off the top of my head. Are SMS alerts something you'd be willing to pay for? Otherwise, are there any set of features that you think would be worth paying for? In any case, I'll give you a free coupon because you are a self proclaimed poor developer and you were the first to post here

Thanks for the post by the way, really cheered me up!

[poordeveloper]

(Wow, a reply and a positive one at that!)

> Do you plan on charging for the service? And specifically for SMS/email alerts?

I haven't given much thought about that yet. I do plan to find a way to generate revenue eventually (at least to keep the lights on and keep my stomach full if I'm lucky) but I'm not sure what form it will take yet. I think I will probably go with a freemium type model: a free basic version and a paid version with additional features. Or have a free web app and sell a paid mobile app? Or make it free for wallets with less than X BTC and paid for wallets with more than X BTC? Or have everything free but charge for API usage? Just run on donations and hope that BTC will go to the moon?

Those are just some ideas off the top of my head. Are SMS alerts something you'd be willing to pay for? Otherwise, are there any set of features that you think would be worth paying for? In any case, I'll give you a free coupon because you are a self proclaimed poor developer and you were the first to post here

Thanks for the post by the way, really cheered me up!

I'm glad I cheered you up I really see a need for this service, people don't have the time to monitor their wallets 24/7 and with your service this would be possible.

I can  see many of those ideas are viable. Others (like only charging wallets below X BTC) would only lead to abuse (people would create many smaller ones).

Definitely, SMS alerts is something I'd be willing to pay for (with a good gateway so no messages get lost / undelivered) since I believe it's the most reliable way to get notified almost anywhere in the world.
If the wallet is very important to me, I'd pay to have another backup gateway (In case no SMS delivery confirmation, the message would be sent through another provider). This could be an extra service on top of the normal one.

Maybe you could implement a freemium model with a limit of features per period of time (for example, maximum 10X email notifications and X SMS notifications per month in the free plan, and so on for each paid plan).

I assume, since you said you wrote a wallet, that we'd be notified of TXs immediately - so this would be a great service.

Thanks in advance for the free coupon, really appreciate it

[maxrann]

- Better UI (display the list of transactions in a smarter way, awareness of change addresses, etc.)
- Registration/login: ability to save wallets
- Receive email / SMS alerts when transactions occur
- API and web hooks which let users execute specific actions when specific transactions occur
- Ability to create new transactions in order to sign them offline
- Support for BIP32 HD wallets
- Some nice visualizations and graphs
- Your suggestions

BUMP! I have just implemented basic user registration/login and ability to save wallet but I have to admit I haven't done much testing yet.

[maxrann]

- Better UI (display the list of transactions in a smarter way, awareness of change addresses, etc.)

Another update today The wallet show now display transactions in the same way as the Electrum client. Much better to understand what's going on now.

[maxrann]

Just implemented a currency switcher in the footer so you can view your wallet in BTC, mBTC or USD (latest price from bitstamp).   

http://oi60.tinypic.com/2hxum15.jpg

[maxrann]

Bumped! Improved wallet UI. It's now possible to filter by address and get transaction details by clicking on a transaction. Also, fixed a couple of bugs (large wallets can now load - although slowly. Still haven't implemented server side paging/filtering).

Armory wallet support on the way.

http://i59.tinypic.com/mtmmgm.png

[tmu]

Hi,

Promising thing, thank You.

I did encounter some error.
One address working ok but other one was giving me error "Cannot call method 'to strig' of null".
After that tried first address again and working but still second one giving error.

Both addresses working with other applications (svallet.info).

Can't get images working 
https://app.younited.com/?shareObject=a47f1acf-825d-235a-d3d8-8270a878f443


-tmu

[maxrann]

Hi tmu,

Thanks a lot for reporting this bug! I believe I have fixed it, could you confirm it is working now? PS: coldmonitor is a bit slow for transactions with many txins/txouts but we're working on that. Also, any feature you'd like us to implement?

Cheers,
Max

[maxrann]

Bump! ColdMonitor is now in beta testing as an app on the Android Play Store. Shoot me an email if you'd like to try the app: hello@coldmonitor.com

https://i.imgur.com/GFOTryil.png

https://i.imgur.com/T2veAZml.png

https://i.imgur.com/K346o9dl.png

[tmu]

Hi tmu,

Thanks a lot for reporting this bug! I believe I have fixed it, could you confirm it is working now? PS: coldmonitor is a bit slow for transactions with many txins/txouts but we're working on that. Also, any feature you'd like us to implement?

Cheers,
Max

Hi,

Yes it is working now.

I do have feature i would like to see.
Jolla/Sailfish application.
https://jolla.com/
https://sailfishos.org/index.html

And no I won't contaminate my Jolla by using adroid apps

-tmu