The Keeping Up With The Kardashians star delayed the release of her project to make some last minute adjustments but now it's live and, like her sisters, mixes free content with paid-for content.
Kourtney told fans: "My app is definitely going to be different from my sisters. I'm going to share the things I'm passionate about like interior design, recipes, style and beauty; and I'm a mum of three so you will definitely get insight into my mum life. I cannot wait to share my life with you."
She added in a written message: "Shaking things up a little :) I'll be bringing you most of the week's content at once so you can dive in when YOU have the time!"
Kourtney's sisters Kim, Khloe, Kendall and Kylie launched their apps back in September, with Kylie's being the runaway success, outselling the others after 24 hours on release.
According to reports, nearly one million people downloaded all four apps in just one day, with 74 per cent of those downloads for Kylie's app alone.
All five apps offer a mix of free content and paid-for features which can be accessed by paying $2.99 per month. The apps all reflect the individual sister so Kylie's focuses on her love of make-up, Kim on fashion, Khloe on fitness, Kourtney on motherhood and Kendall has gone for adventures, perhaps because of her jetsetting lifestyle as a model.
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