There's plenty going on in the in-app advertising market as developers look to supplement App Store sales with other revenue models.

To that extent, mobile ad network GreyStripe is pushing at an open door.

It's just extended its strategic relationship with ad technology company Tapjoy so developers can run fullscreen Flash ads, which are transcoded for iPhone delivery and deliver a higher CPM than static banner ads, via the Tapjoy SDK.

"Tapjoy is excited to improve and broaden our service by offering a full-screen ad option to our users," said Lee Linden, co-founder of Tapjoy.

"It's even better that Greystripe provides a unique, rich-media format. We believe this will increase publisher revenue far beyond what is currently available."

"When done transparently, mediation companies offer developers a great way to maximise their revenue and control over the advertisements within their applications," added Greystripe CEO Michael Chang.

"We're excited to be working with Tapjoy to widen our base of developers., and bring Tapjoy's unique services to our developers."

You can find out more via Tapjoy.com and GreyStripe.com.

Or read our interview with GreyStripe CEO Michael Chang - Price deflation is driving the uptake of in-app advertising.