People skilled in developing applications for mobile phones and tablets are in hot demand, says online freelancing network Freelancer.com.
Freelancer.com is an "outsourcing" website through which employers can hire freelancers in areas such as software, writing, data entry, engineering, the sciences, sales and marketing, accounting and legal services.
The site has more than three million users.
Freelancer.com on Thursday released its survey of online job trends over the first three months of 2012, which included the 50 fastest growing job categories.
"The demand for mobile (application) developers has been insatiable and will continue to grow as more businesses seek to offer their products and services on these platforms," Freelancer.com said in a statement.
As sales of "post-PC (personal computer)" devices outstripped those of personal computers and new models came onto the market, the number of jobs in these areas had increased.
The number of freelance jobs available for Android apps rose 26 per cent to 2,863 compared to the fourth quarter of the 2011 calendar year; jobs for iPhone apps lifted 27 per cent to 4,318; and iPad was up 19 per cent to 1,828.
Nonetheless, Android was ranked only 23 on the list of the fastest growing job categories; iPhone at 25; and iPad at 35.
The top five fastest growing job categories were led by Business Process Outsourcing (up 303 per cent), which is the outsourcing of "back-office" and "non-core" functions.
That was followed by PDF (up 227 per cent); Excel (up 200 per cent); Data Processing (up 187 per cent); and Copy Typing (up 152 per cent).
Twitter was ranked 17 (up 39 per cent); You Tube at 20 (up 31 per cent); eBay at 27 (up 26 per cent); and Facebook at 36 (up nine per cent).
The data was extracted from 172,936 jobs posted on Freelancer.com in the first quarter of calendar 2012.
Freelancer.com chief executive Matt Barrie said the number of jobs posted had risen by 30 per cent compared to the prior three months.
"We have seen a huge increase in outsourcing on the whole, with businesses rethinking their strategies moving into the New Year," he said.
Mr Barrie said businesses were trying to cut costs given the widespread economic slowdown and viewed the use of online freelancers as a profit driver.
Small to medium-sized businesses (SMEs) were turning to freelancers to provide around-the-clock customer support.
SMEs were also outsourcing office administration as a result of the comparatively low cost of off-shore labour.