Web & mp3, No pronunciation scores, Free, ★★★★
BBC has free beginning courses in 10 languages (Mandarin and European, but not English!). They also have 12-20 phrases in 33 others. (Hello. Yes. I don't understand...) Text, pictures, and sounds are used, but no feedback on your pronunciation.
A momentary graph shows their (not your) pronunciation of phrases, but it is not clear whether the graph shows pitch or volume. A standard spectrogram would be more useful, or the tone graphs provided by Transparent and Tellmemore. BBC does explain Chinese tones and they check if you can recognize them.
These are substantial, professional, free courses. The only slight drawbacks are the lack of pronunciation scores, inability to choose simple words and personal interests to start with, and being tied to the web while learning.