The program recommends using the moveable do system of sol-fa as it is the best way to learn sight singing. (For those of you who have been brought up with sing by numbers or the fixed do approach feel free to try and explain to me how those system work but I can assure you that you won't be able to convince me that they are better than moveable do!!)
Each exercise is set out with the same format and has a menu at the top of each example. As you can see below you can hear the example in full, set how fast each example should be sung, listen to the tonic note or the note set (in the example below there are 5 notes in the key of G that are used), read the example with the solfa and letter names.
A personal account only costs $30AUD per year and you simply login to your internet browser on any device and you will be able to track your progress through the various 400 exercises that you need to complete! Don't be put off by the number of sight singing examples they are divided into four parts, starting with only 2 notes and continues through modes and chromatic notes in Part D. (Click the slideshow below to see the melodic and rhythmic elements covered in each section - this can be found on the FAQ page)
As an award winning website I highly recommend it to anyone who wants to improve their aural skills.