Topic: Cointra - Your favorite exchange on your mobile and tablet (Read 3700 times)

Awesomeness I'm looking forward to trading through the app on mintpal!

We're getting ready to release the next build with MintPal support in a day or two. Feel free to request other exchanges here!

We are seeing gradual adoption and are giving it its due time to get noticed. So far feedback has been great and those who are using it can't trade without it!

How's everyone liking this app? Just from Google play store it has 5 stars, 100+ downloads, and 11 reviews.

Unicoinex is doing a good job on keep it updated and free from bugs, I'd like to see more reviews and downloads though since I helped test it

Bump for COINTRA!

Update 29 released. Fixes force close on startup, please update if you're facing this

Well adding the search button didn't leave enough space for chart button to stay visible. Its actually done by os itself based on screen size. On larger screens it will still show the chart menu, even on landscape mode it will still show. Can you suggest one thing though, it currently shows 2 buttons (search, refresh) and 2 in soft menu (clear, chart), in your opinion which two buttons should be visible and which two should be in soft menu?

One more thing, the pinch zoom just zooms in and out, while the chart menu allows selection bar unit size (1m, 3m, 5m... etc), two different things.

The button for viewing the chart has been changed to the soft menu button. Is that to move us towards using our fingers to zoom in and out?

Just curious. I've pretty much zoomed in/out with my fingers since the beta test so it's no big deal for me.

Just bugfixes in the latest update. We are working on the new features (both auto trade and mining toolkit) which should be coming soon though.

Thank you. Now I can feel better about checking my portfolio and watching trades while not on wifi. I never had an issue with the battery being drained but it's good to know that on the network it's still not going to bleed the phone dry.

I noticed an updated today, anything special added?

ok ~18 hours it used 40MB of data and 5% battery. I switched the app to foreground around 8 times, during every session I checked at least 4 exchange/pairs and also watched the chat between 10-15 minutes every time. Please note that I kept the app running in the background (it keeps updating the charts every time the phone awakes if kept alive in background). Usage should be down 90% if you just start the app to use and then close from task manager after usage. YMMV

Awesome. Lame AT&T likes to limit its users LTE data usage so I would greatly appreciate any information about how much it uses so I don't have to test it myself.

I will post some numbers on data usage. Will run it for one day on mobile data only.

We're you able to see how much data it uses when not on wifi? I don't have a large data plan to test it.

I had a chance to check out this app - it's really cool. Very convenient for day trading on the go.

That search option is freaking awesome. I had like how the coins would be at the top if you had balances but when you're searching for a coin and have to scroll was a time waster

Starting with build 26 we have moved to staged rollouts. So your version might not update itself for a few days after release. This is to make sure that if new version introduces any new bugs, they don't affect the majority. If you prefer the cutting edge you can always update manually from play store.

Talking about requests, you and a few other asked for more control on trend chart, well just released build 26 with that functionality! You can now select more than 4 exchanges (it still warns that more than 4 can affect performance) and you can select any exchange/pair irrespective of the selected ones. This will allow you to for example watch DOGE/BTC market while you trade BTC/USD market.

Also added is brand new Search to switch functionality! No need go to navigation drawer to reach the coin of your interest. Just type pair or exchange and switch to that coin right away!

Screenshots:

You guys have such a fast turn around on updates and request!

Thank you for your feedback. Your suggestions and recommendations during the beta testing and even after that were crucial in shaping up the app.

I've got to say it was an absolute pleasure being able to work with you Cointra. I've never seen a developer who listens to the feedback from its users, takes it seriously, and acts on that feedback as well as you. You get an A+ for communication too.

Russian Translation already in. Included in release 25. Will be updated everywhere in a few hours as Google replicates it everywhere.

Few exchanges currently have advanced orders (Kraken and Bitfinex being the popular ones) and while we actually added margin order support to the API (for Krakan and Bitfinex only), we didn't add supporting screens and for the first release decided to not include margin trades. If there is enough demand for advanced trades, we will include them. I will consider your post as the first vote for advanced trading!

cointra,

Any plans to add support for Bitfinex margin trading functions?  Thanks.

Glad to know you like the app and find it useful. We are working on many new features, two major enhancements you will see in a few weeks are auto trading rules and Mining Toolkit. Mining toolkit will allow you to monitor mining rigs, mined coin difficulty and profitability and other mining related info right within the app. Auto trader will allow automatic trading based on simple rules but without keeping your phone awake or draining your battery.

Besides the new features we are working really hard to make sure any problems faced by users are handled immediately and resolved fast.

Glad to see the app is getting noticed!

This app is extremely useful and a lot easier then trying to use your phones browser to trade or check current rates. I've had no issues with the app crashing. It's good on my battery, not like some apps that suck it dry if you don't force close it. I haven't tried using it for long periods while on 4G data since I have a small data plan however with WIFI being almost everywhere it's not a problem.

Not sure what more you can add to the app but I'm sure you guys will find a way to make it even better!

Added Video instructions on how to generate BTC-e API for use with the app. Videos for other exchanges coming soon.
Edit Also added Bitstamp API Key instructions video. Check the 2nd post.

We don't transmit the API keys to our servers so trade has to happen from the device. We are using a different mechanism where the device can sleep and still the rules can be used effectively. If you want details I can PM you.

Of course, it's completely normal - you can't test every device in the world with every possible configuration before releasing the app
Adding those simple rules would be useful, although it would require to always keep the app running (or else the rules wouldn't apply - unless you do it server-side).

Force close on certain I9100 and N7000 resolved in build 24. Please wait for update in an hour as it replicates on Google servers

Absolutely open to the idea. Any trusted member can contact me for code review.

Would you accept having a trusted member audit the code for security purposes (instead of open sourcing it)?
There's been too many problems due to viruses...

Automated rules were requested by one beta tester as well. It in our enhancement list, since the objective was to keep it simple, we didn't include them in the first release. We plan on adding very simple rules down the road (buy when +/- X%, sell when +/- X%, stop when +/- X%).

Its the first public release so we knew we will face bugs, the app runs on around 4100+ devices, and they can have many different OS versions, with some people using cutting edge unofficial versions, bugs are sure to appear!

Great to see you're trying to solve all bugs as they appear.
Do you plan on supporting automated trading based on specific rules?

Thank you guys for reporting the issue with GT-I9100 force closing. Issue seems specific to this phone! Working on a fix for the next build.

Chinese translation has been added to the latest release. Russian coming soon.

I hope you find the app usable. Please leave any feedback you may have here and on Play store. Thank you!

This makes sense to me.  I appreciate the motivated and careful replies to my inquiry.  FWIW, I'm pretty convinced that I want to try it now

Well the app generates charts using data from our servers (that way they're very fast and also your ip doesn't get blocked by your exchange for continuous polling), if it was only client side code pulling nothing from our servers, open sourcing would be a non issue, but in our case the last thing we wanted was 100 other softwares pulling chart data from our server pretending to be Cointra using its API. But again as I said earlier going open source is always an option, we even asked our beta testers to tell if going open source would help, most responded "maybe".

That's a very generous offer. 

I'd take you up on it but I'm not hero level yet.

Anyway, I think your explanation about api keys makes sense and I think I'll give your app a try in a few days when I get a chance to look at my CGB stash and open relevant accounts.

Just for the sake of discussion though, can you say anything about why you *wouldn't* want to provide the source for your app?  Are you worried about someone stealing your code?

We're not using any specific feature limited to newer API as such, however our internal tests showed that older devices lag too much, and the screen estate (majority of old devices have low dpi and screen size) is also not enough to render the charts with other controls efficiently. That and since 82.7%+ are running 4.0+ http://bgr.com/2014/05/05/android-version-market-share-april/ we decided to stick to Min SDK 14. Still I will ask the developers to try to run on lower API and see if we can release with even lower Min SDK.

That API key is not a valid key, it was just an example but I like the idea. I will be glad to create an actual API key on any exchange with 0.1BTC or equivalent in altcoins for Hero Members to test and give their feedback. If they make any profit trading its theirs! I can't post such API key in public primarily because API keys don't work on more than one client at the same time (they require incrementing nonce number which can conflict when multiple devices are using the same api)

Is this a working account which we can use to try it?

Also, I think you'd get way more installs if you lower the API version - unless you're using some specific features, you're only limiting yourself

Minor new release, additional news source on user requests.

Done and ready for the next release. Please check PM for details.

Got your PM and its already in the works! Please do give me the requested details in PM

Sent you a PM 

Here is an example of an API key for a BTC-e account

Key: 821FH6SF-JUFCWRJ2-JUWCHN6L-UC1CPLCP-T8UJSHNK
Secret: 55650306433dd24b1619c9f0337b297e9773e0066ee1cbe77f47042b709c6434

Feel free to ask any questions you may have and I will be glad to explain. Please allow me to explain API keys a little more here also to help other readers who aren't familiar with them.

All major exchanges allow users to generate API keys and secrets, they are separate from your username and password and you can set individual permissions for each API key. For example you can create one key pair and give it only Account Info rights, which would allow any software to only view your account information. The API keys can not be used to log in to the exchange website, instead they are to be used by specialized software to read the data you allow. API keys can be cancelled at any time, so in case you lose your phone you can cancel the API keys after logging in to your Exchange account (in Cointra we keep all API keys encrypted, with added encryption using a PIN if you enable it, so even if phone is lost it would not be trivial for someone to get your keys if you're using a pin).

I understand the need of an open source wallet since the software itself keeps your money! But in case of Cointra nothing except API Keys (not even your email) is stored by the app on the phone, everything is kept on your exchange and it uses the API keys you configure to allow you to view/trade your funds on your configured exchange. If the app corrupts, or phone is lost, all you have to do is delete/disable old API keys by logging on to your Exchange and create new API keys when needed.

I appreciate the detailed response.  Because I haven't yet done any trading on these sites, I'll have to look into the API key permissions that you're discussing, but on an initial readthrough this seems reasonable.

I also run the cyanogenmod rom on my android devices so one nice option I have is revoking permissions even after an app is installed.

I personally think it's pretty crucial to see the source code even if I don't end up compiling it myself.  For example, I run the schildbach Bitcoin Wallet program and I just installed it from the playstore.  However, that was after downloading and reviewing the code.  Note: this was also crucial later when I had to recover a lost wallet file (I could check the source to see how/where it was stored on my device).

I'm going to check out what you said about the API keys but I know that my own personal stance is that if it's not open source, I'm extremely cautious and skeptical.

It is a closed source app but since this app uses API Keys and not Logins, you fully control what level of access the app can ever have. For the mobile security, Android uses detailed permissions specification and the app requires no special permissions besides standard ones that give it access only to its own data and those permissions are shown during the install by Play store.

Regardless of open or closed source, whenever using an API based trading software, one can remove the risks by setting the right permissions on the API key. For Cointra you don't need any withdrawal, deposit, transfer rights on the API keys so make sure you don't add them. You can even start with read-only API keys making it 100% risk free to start.

That being said, we are very much open to your suggestions, and if you believe that open sourcing the app would be a critical factor for you and like minded users, we would consider open sourcing it. So far we have seen that majority of the users don't compile their own mobile apps even if they are open source (based on Play Store install counts of the open source apps, like the Bitcoin Wallet). Much different than desktop apps where majority compile from source (themselves or by their OS distribution).

its not going to be a open source app but so far I have had no problems with the app. I am not a developer of the app just a beta tester. If your worried just enable 2FA on btc-e and set it for withdrawal and security changes.

I'm going to take a look at this.  I haven't done much trading but maybe that was because I didn't know of a convenient platform.  Thanks for the tip!

One question before I download: can I see source code for this app or is it binary only?  If there's no source available I probably won't install because it's hard to trust a closed-source app with money.

I beta tested this app and I must say this app is amazing. Please support the developers as they are hard working people. The app allows you to check and trade your cryptos on your phone with ease when on the go. Also any problems or bugs are resolved quickly with their support. Feel free to ask me any questions in pm or in this thread about this app or the developers.

Videos

• How to generate BTC-e API Keys for adding to Cointra
• How to generate Bistamp API Keys for adding to Cointra

Release Notes

1.0 build 22
- News source CoinBuzz added
- Cryptsy new added pairs now instantly available

1.0 build 24
- Chinese translation
- Fix force close on some I9100 and N7x00 phones

1.0 build 25
- Russian translation

1.0 build 26
- More control over trend chart
- Search functionality
- Much improved chart/ticker load times