Set up by siblings Emma and James Sinclair, EnterpriseJungle now works with some of the biggest companies in the world.

Their HR solution helps large businesses manage alumni and retirees to increase talent pools and reduce internal costs.

It is the first platform of its kind, and provides users with access to discount offers and events.

See more of our 101 tech start-up disrupters here.

And check out our 101 rising stars of tech - the exciting firms which did not make the main list but have the potential to grow.