The rush to free promotion continues apace with two very different games gaining exposure over the weekend as they switched from paid to free.

First up was Com2uS' Heavy Gunner 3D, which went from $4.99 to free for three days, before resetting as a $2.99 paid app.

Promoted as part of the FreeAppADay website, it became the #1 free game on the US App Store within 15 hours; the fastest ever rise, according to FAAD's Joe Bayen.

"Com2uS may seem to be giving away an amazing product for free but in return we hope that customers will know the type of top-notch games that Com2uS has to offer such as Homerun Battle 3D and Inotia 2," said spokesperson Miji Kim, referring to the cross-promotional benefits.

Dancing to the free beat

Also gaining from free promotion - this time with OpenFeint's Free App of the Day - was the Mobile Pie developed and Tag Games published B-Boy Beats.

This dropped from 99c to free on Friday 23 April, doing 60,531 downloads over the following three day period.

"We're hoping it will create a viral effect that will give us a sales bump once we return to a paid model, and if that goes well we'll continue with a good tail through word of mouth," said creative producer Will Luton.

"If we have a large captive audience that will allow us to sell future games to them.

"And on a personal level, we put a lot of effort and love into making this game so it's brilliant to see lots and lots of people enjoying it. If we make some money and raise our profile too, that's great."