Android: Most brokerages charge you every time you buy or sell a stock or ETF. Robinhood, however, lets you trade for free and is at last available now for Android users, as well as those on iOS.
In addition to charging $US0 commissions on trades of US-listed securities, the mobile app also has features like seeing your portfolio and personal watchlist at a glance, getting real-time market data and quotes, and quickly signing in with a custom PIN code. All the data is encrypted and your securities are protected by the SIPC, which covers up to $US500,000.
Currently you have to be a US citizen to use the app, however its website has announced it's "coming to Australia", and currently lets you sign up for early access. You can do that on its website.
As usual with free products that sound too good to be true, you might be wondering what the catch is. The company says it makes money in many of the same ways as traditional brokerages, by collecting interest from customers' uninvested cash balances as well as from those who choose to upgrade to a margin account.
Robinhood [Google Play]