Overleaf - The online platform for scientific writing. Overleaf is free: start writing now with one click. No sign-up required. Great on your iPad.
Vanido - Vanido is a singing coach in your pockets.
TeXworks - The TeXworks project is an effort to build a simple TeX front-end program (working environment)...
Singscope - See your pitch analyzed as you sing
TeXstudio - TeXstudio is an integrated environment for writing LaTeX documents.
User Inyerface - A painful illustration of bad UX