It used to be 24 hours on Android, but too many people got refunds on games after they were done with them in a day.

It could make more sense to leave the period up to the developer to decide (with a few options to choose from).

I have the TPB return policy.

Download it when I'm interested what it's like. And delete it when/if I'm done.

A 24 hour/15 minute return policy is just an insult.

I notice that at no point in this process is actually paying for anything mentioned...

I also wouldn't trust any app on my phone which I have downloaded from TPB. I barely trust any app I download from Play Store!

It'd probably be helpful if the store let the developer set the trial period. An appropriately set period is going to vary by what the software does and the devs/publisher are the most likely to have (a) the necessary insight involved and (b) the highest incentive to get it right.

I heard people would buy an app, "backed it up" with Titanium backup, get a refund and restore. Not sure if they put something into Android/Play now to counter that though...