Great that you came back and continue to support this widget!

Kudos to you!

Well, the question wasn't clear, so that answer could be misleading.

You can _purchase_ the software only with bitcoin, yes.

But you can trade all the coins that the different exchanges included can trade.  So not only bitcoin, no.

If you didn't change your executable, your keys will always stay valid for leonArdo.

The "valid" keys (actually the first half) are built-in the executable itself.  That is why Jonathan needs to re-build a version for every new purchase.  So it doesn't depend on an external server or database to check on that.
And think about it:  If it would depend on an external server to check the validity of keys, then all copies of leonArdo would stop working iof their server would be down, or if the company would cease its operations.  Not a good model.

So, logically:
If you changed your executable, then I'd suggest you to revert back to the one you were using successfully before.
If you are using the same executable as before, then my guess is that Poloniex (if that's the one you are using - which one is it?) has banned your IP, for a reason or another.  It does happen sometimes - too often, actually.
Try connecting from another IP.  (And make sure there is no IP whitelist in place for your keys - I don't know if Poloniex has that feature.)

Or try deleting leonArdo's setting folder (or rename it to make a copy beforehand), in case some file was corrupted and leonArdo was somehow sending a corrupt key.  That way, you'll be forced to re-enter your keys when starting leonArdo again, and you'll be sure that you'll be using the correct keys.

That would be a very useful feature.  The reason behind it is that, if I look at the chart of a random coin, I have no easy way at first to know about the _amplitude_ of the variations.  Is this coin going up and down by about 1% or 2% throughout the day, or is it going up and down by 50% or even 200% during that period?  (or anything in-between?)
It would be useful to know that, with a quick glance, without needing to use the ruler tool.

Great idea too.

Sorry about the delay, I was away.

This "Note" feature would need to be connected to specific pairs.  So it could be a pop-up text window, that could be accessed by a button near the "Trading strategies for XYZ/BTC" (around top-left of the screen).  Some sort of pop-up window that would look similar to the "Balances" window, but with a simple, plain text editor field.  And that button would be in bold (or whatever visual cue you can devise) when there is some text in that note.  And an auto-save of the text, every time that window is closed.

A suggestion of a feature that would be useful for me:

The possibility to add some "notes/comments" for myself (just text-based) on the different pairs.

The reason for it is that I often look at different pairs (30 to 40 different pairs), make my own analysis, and then see that the time is good or not good to trade on it, then move on to another pair.  And the next day I don't always remember what mya analysis at that time was, so I have to re-spend a few minutes per pair to re-check things all over again.  With 30-40 pairs, you can imagine it can be lenghty.

Here is a real-life example:  E.g. There is a pair I like to trade, but now there is a big surge, and I expect it to crash in the short term, so I won't trade on it for now.  So it would be helpful for me to have a "post-it" type of note, where I would write for myself, for instance: "Crash expected, check after Sunday".  Or another one:  "Market always goes up after a drop.  Hold longer."

Something quick & easy, simple plain text, not a full WYSIWYG editor.

Great - thanks for that!  I hadn't noticed it, indeed. 

Is there a way to disable entirely the (now defunct) BTC-e market from leonArdo?  Or to get a version of leonArdo without it?

It did happen a few times that I clicked on adding the BTC-e market by mistake (while wanting to add another market or another pair), and then leonArdo is stuck with it:  There is a little moving "wheel" sign at the location of that menu (to show that leonArdo is working), but nothing else happens.  There is no other window that show up asking me to enter my keys, no other menu is coming up, and I cannot make "cancel" anywhere.  It is stuck at this "wheel" spinning, and the big problem is that I cannot add any other market or currency anymore.  I need to close and re-open leonArdo entirely - which can be long to do when I have many bots running.

The history of the recent ZRX coin on Poloniex is not appearing, and disappears after restarting leonArdo.  Is it possible that the collecting service needs to be restarted?

Indeed, if you are at block 304097 (while the latest is currently 477579), then you are not sync'ed up, and Armory can't see that transaction and your balance.

I do not know how to fix your issue, though, just pointing you towards what needs to be fixed.

Great, good news that you are on it!  Keep up the good work! 

Any news about updating the Bitstamp API?

Bitstamp added LTC a week ago, will add ETH shortly, and also has added XRP a while ago.

Currently, there is a strange bug:  If you buy/sell Litecoin on Bitstamp (through their website), leonArdo will pick that up on the API and will display it as a buy/sell of BTC.  So you'll have a notification that tell you, for instance, that you bought 100 BTC at @ $35 USD each!

Thank you for that.

For SC on Bittrex, I still see only a few weeks of data, so I suppose there must be some corruption on the local DB here, since it is a coin that exists since a long time (and I do not think anyone else reported an issue with historical data for this coin?).
Is there a way for me to force the re-sync of this coin's data?  Like maybe deleting the file ".downloaded.db.tmp.scbtc"?

I am having the same issue (unable to see historic data), but only with certain pairs.

For some strange reason, every time I close and re-open leonArdo (or after it crashes), the BAT/BTC pair on Bittrex comes back with only has about 2.5 hours of data - all the rest is empty.  It doesn't seem to be able to sync with your data-collection service, and it looses all data it had collected by running here after a restart.

Also on Bittrex, SC/BTC suddenly lost all past data on June 3rd, about 4-5am.  It's as if the coin got created there.  I cannot see anything of the past.

Is there any specific DB file for the coin I could try deleting in the .leonArdo folder for those?

Poloniex's API is totally unreliable at the moment.

It feels like trying to set up an outdoor ping pong tournament (the real one, with little plastic balls) during a great storm.  It might not work out as expected. 

That's also my experience:  Often, Poloniex is totally unresponsive on leonArdo through the API, and instead I just go the the website and manually make buys & sells there, and it works fast and reliably there.  It did happen that I placed, canceled re-placed a sell order 20 times through the website of Poloniex before leonArdo could cancel and replace even 1 single order through the API.

That's true - but some exchanges delete older trade history after a while (3-6 months?), I believe.  I know some people were finding it difficult to make their taxes because the exchanges didn't keep their entire trade history.
I can't imagine the size of Poloniex's trade history of all users, on all coins, for the last few years! 

+1

I would also find it useful.
Even better:  To have be able to specific my 3 or 4 "preferred amounts" (e.g.  "0.1 BTC", "0.25 BTC", "1 BTC", "2 BTC"), and have a little icon for these amounts so that I can simply click quickly to set the purchase amount.  Easy, quick & fast.

It would be ideal that we could all choose our "preferred amounts", so that it would serve both those who trade by buy/sells of 0.01 to 0.05 BTC at a time, and those who trade big with buy/sells of 5 to 10 BTC at a time.

Great - looking forward to that!
And good work, dev team!