Those stream testing programs are pretty much useless. When you consider all elements of streaming (speed, stamina, accuracy and aim), the only way to really test yourself is with real maps.
A general way to improve in the main areas of streaming would be:
Speed - Play lots of maps with burst streams (short streams) above your comfortable limit
Stamina - Playing maps with longer streams than you are usually comfortable with
Accuracy - Playing streams around or under your limit while focusing specifically on fluid and consistent motion that allows you to match the hitsounds to the music as closely as possible. If you're playing a map with a relatively low aim requirement you can even look at your error bar to adjust to the live feedback during play.
Aim - This will mostly develop on its own just by playing higher star rating maps. You'll encounter increasingly spaced streams as you play more difficult maps. As long as you aren't avoiding specific map types and playing a good variety your stream aim will improve as you improve at the game overall.
A general way to improve in the main areas of streaming would be:
Speed - Play lots of maps with burst streams (short streams) above your comfortable limit
Stamina - Playing maps with longer streams than you are usually comfortable with
Accuracy - Playing streams around or under your limit while focusing specifically on fluid and consistent motion that allows you to match the hitsounds to the music as closely as possible. If you're playing a map with a relatively low aim requirement you can even look at your error bar to adjust to the live feedback during play.
Aim - This will mostly develop on its own just by playing higher star rating maps. You'll encounter increasingly spaced streams as you play more difficult maps. As long as you aren't avoiding specific map types and playing a good variety your stream aim will improve as you improve at the game overall.