Launched in 2001 as an online fundraising platform, JustGiving has helped 13 million people raise more than £1 billion for 13,000 charities.
Facebook is a key driver in helping fundraisers share their JustGiving activity, driving more than a million donors to the online giving platform in 2011.
Last September, the charity launched new tools to help people share their donations with Facebook friends, and research suggests this has resulted in an additional £1m in charitable donations to date.
The new Timeline app enables fundraisers and supporters to add charitable donations to their own Timeline, and update it when they give money using JustGiving.
As well as helping donors "showcase their generosity", the app will allow fundraisers to thank the people who have supported them using a "thank" action.
Currently around one in ten donors share their donation on Facebook, but JustGiving hopes that Timeline integration will boost this figure even further.
According to JustGiving data, each viral Facebook share is worth an average of £5 in donations to a fundraiser's charity.
Users will be prompted to use JustGiving's timeline app when they donate through the site.
"JustGiving is committed to ensuring charities have the very latest technology to help them raise as much money as possible through social media," said JustGiving product manager Jonathan Waddingham
"By launching our new Timeline app, we aim to increase the number of people sharing their charitable giving online and increase the impact of those shares.
"We know that sharing drives donations - and by helping people to give a public display of recognition to their supporters, we predict this will help raise even more for worthy causes."