Overleaf - The online platform for scientific writing. Overleaf is free: start writing now with one click. No sign-up required. Great on your iPad.
TradingView - The best charting tool for crypto and stocks
TeXworks - The TeXworks project is an effort to build a simple TeX front-end program (working environment)...
eToro - The social investment network that connects traders from around the globe and enables them to share...
Texmaker - Texmaker, free cross-platform latex editor
Robinhood - Free stock trading service.