Here is a master list of all of the FREE German learning resources online.
I put together a comprehensive list of all of the free online resources to learn German, including video, apps, podcasts, courses, dictionaries, websites, textbooks ... you name it. The complete list is here: http://gratisglobal.com/learn-german-free/
If I missed anything at all, please let me know so I can add it. My criteria are that the resource must be free, useful and high quality. I do include apps and programs with the "freemium model" as long as the free offering is substantial enough.
Hope this is helpful.
One way of learning German which you have missed off your list is learning it through music, some of us learn great through music and its an interesting way to supplement german lessons. So maybe you can add in a song section of german songs recommended to help learn..
Some german music which can be helpful which i recommend is - (for helping learn German numbers and some other words) check out the song by Rammstein called "Sonne".
Other german songs which Im finding i sing along with as they are slow,have a lot of words Ive already covered at duolingo, or a few easy lines to sing are (look these up on youtube so you can see both german and english wording)
Seemann lyrics german english Rammstein (the channel is welcomehell)
LaFee - Ich Bin Ich/This is me (English translation) (BlueIris1320 has it translated on her channel)
Faun-Diese Kalte Nacht (with lyrics and English translation) (Anuja Deore channel)
Louise" - Eisblume (English Translation & German Lyrics On Screen (its on RiceBunny17 channel)
- Faun ~ Wilde Rose (With Lyrics & Translations) (channel -SteamPowered Account)
more good for learning translated videos on BlueIris1320 channel - LaFee - Hand in Hand (English translation)
Lafee - Wer Bin Ich/Who Am I (English translation)
LaFee - Lieber Gott/ Dear God (English translation)
LaFee - Ring Frei/Fight (English translation)
-LaFee - Zusammen/Together (English translation) ....... - Das beste Silbermon (channel Ha Tran)
A few I use on youtube and are worth checking out - Learn German While You Sleep 150 Basic German Words and Phrases" its by Trieu Duong HUYNH (unlike the other learn german while you sleep videos on youtube, this one is easy to fall asleep to and great for those just starting German).
For the little bit more advanced learners (Im starting to find this good at level 13 Duolingo) there is"Learn German Conversation" . The Learn German Conversation videos are by "the language channel" on youtube
Also on youtube the videos from Andrea Thionville are good for learning too (these focus on various subjects (I suggest this to those about level 10+ at duolingo)
Also - "LEARN GERMAN FOR BEGINNERS" on the channel "Learn German with Anja " This is a 50 video beginners course on youtube. I highly recommend this for all levels of beginners and for each video lesson most are under 5 mins. I started to learn quite a bit of German through her channel before I found duolingo.
Thank you for that very useful link.
The "free" resources that I have found most helpful with my German recently are my Netflix subscription and Google Phrasebook.
Obviously Netflix is not free, but if you have a subscription to watch in English you may not be making use of the German language films and TV which are freely available with German subtitles. I find this a great way of improving my vocabulary and my aural German skills, as well as watching some interesting dramas. I have just finished the six episodes of Charité, a historical medical drama, and really enjoyed it.
With Netflix the subtitles remain on the screen when you press pause, so I use Google Translate to look up unknown words, and can save all the words I look up to Google Phrasebook, so that I can go back over the words I have looked up. These words can be saved to a spreadsheet or imported into flashcard programs.