Which application do you all use for stocks trading with low brokerage fees?

Td Ameritrade for US stocks. Zero comm except for misc exchange fees which are negligible. Powerful tools to run custom charting and watch list scripts. Easy to use mobile app as well.

I mainly use it for options trading.

Interactive brokers.

There's a $10 monthly minimum, but that drops to $3 a month if you are 25 or younger, which I am. US market trades are at USD 0.0035 per share and at a USD 0.35 minimum, so I usually pay USD0.35 per trade with my small trade sizes. Plus I do trade options, so I easily pay more than the $3 minimum.

On top of all those, IBKR's FX spreads is the best that I know of. Their margin rates are also the lowest at around 1.59%.

One of the awesome features I've yet to use would be the 1 free withdrawal per month. Otherwise, its' SGD15.00 by wire and SGD1.00 by BACS/GIRO/ACH/EFT/SEPA.