Workaround for seeing weekly progress chart
I've written a user script which adds a weekly progress chart to the home page (though it looks a bit different than the original chart) http://www.code-poet.net/duolingo/weekly-progress.html
It will also let you see other people's weekly progress on their profile (with some limitations as described on the page I linked to).
I'll try to keep this script functioning until Duolingo puts their chart on the home page again, or adds the new "coach" feature.
I'm not sure why it was removed, but in Duolingo's defense its sometimes faster for a user to add a feature than it is for Duolingo to add it (once they make the data available, which thankfully they did in this case).
I only tested in 2 browsers (Chromium and Firefox), 1 OS (Linux) and 2 site languages (English and Spanish) while they have to test a much wider range of environments and configurations. I've deliberately ignored browsers that can't run Greasemonkey-style userscripts since Greasemonkey's API makes things simpler for me.
Also my script is still unfinished. The output you see in English is accurate, but I translated the Spanish output myself so it could probably be improved. Somebody using the site in another language will see the output in English instead of their own language. Duolingo can't do such an incomplete release.
Anyway, I've never used the iOS app so I've never see the coach feature, but hopefully it will be better than my chart once its reaches the site.
Awesome! And even better than the original coin stack... (Fire)Man, best UserScript ever!
Edit: I am staring at the chart constantly. Can't keep my eyes off! I can't even express in words how much I appreciate your script. Really.
Edit 2: After a while it almost feels as if were there forever!
I see that I still have this addon enabled in my browsers, but it's not showing up any more. Is that because they have enabled the coach feature?
I don't want to use the coach feature, but I do want to see how many XP I have got in each language so far each day.
Well, I guess I could turn on the coach feature if it allows me to set a daily goal of 1 XP. But after seeing someone say they lost their streak when they turned on the coach, I'm childishly worried about that happening to me.
I haven't used Opera since before they changed their layout engine from Presto to Chromium (edit: I mean Webkit/Blink). Back in the Presto versions there was built-in support for user scripts (they were the first browser I know of to support it) but it didn't provide the Greasemonkey-specific features that my script uses. I don't know how if changed since the switch to Chromium. Maybe they can now use Chromium extensions, or maybe that was one of the features that disappeared during the switch.
If you can confirm that current versions still support user scripts I can try to remove the dependency on Greasemonkey so the script works in Opera. I can't check because they no longer support Linux.
I'm using Opera 20.0 on a Win 7; Version information
Version: 20.0.1387.77 - Opera is up to date Update stream: Stable System: Windows 7 64-bit (WoW64) Browser identification
Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.149 Safari/537.36 OPR/20.0.1387.77