Boost is introducing 2x new mobile plans tomorrow (Oct 25). The first is a $30 plan with unlimited national calls and texts, plus up to 7GB data over 28 days. The second is a $10 plan with unlimited national calls and texts, but with a 7 day expiry. Boost uses Telstra's 4G network. Enjoy :)
Note: thanks to aroryo & Maxx Power in the comments for pointing out that setting up auto-recharge gives you a full month of service, irrespective of number of days in that month.