The free app allows you to build a family tree from scratch. It 'talks'to www.Ancestry.com.au (basic membership of this site is also free) & can provide hints. Use dropbox, evernote and puffin (open flash images) apps to assist with reading or recording information.
Free to search index but you have to pay $1/page to view (up to 20) matching records & $18.50 to view the whole certificate as a digital image.
NOTE: due to privacy rulings searches are only possible online for the following years; births (1836 to 1908), marriages (1836 to 1942), deaths (1836 to 1985) See: http://www.coraweb.com.au/bdmaut.htm for a list of other state sites which all operate differently.
NOTE: check if you can search the BDM indexes for free at your local public library.
Can be used for free by members at Yarra Plenty Regional Library branches. Main focus is Britain & USA/Canada but does include some Australian. You can also use their free software to store your family tree data.
Free to search index but costs $25 for the first full copy of a document & $3 for @ document after that.
Also consider criminal records in other countries, eg http://www.oldbaileyonline.org/ London criminal court 1674-1834 - free excellent source for a general background on London & crime as well as full accounts of court cases.
Free. Search for Australian/Victorian historical photos or articles in Australian/British newspapers. Some databases require you to be a library member & two (ancestry.com & findmypast.com ) require that you use them in a branch.
YPRL also have many other indexes (online/microfiche, Australian/British) that can be searched for free at select branches, eg DV or Ivanhoe.