Android (rooted): Every once in a while, you hit up the Play Store only to find that the app you want "isn't compatible with your device". Want to try it anyway? Market Helper gives you the power to do so.
Sometimes, apps are incompatible just because they weren't made or tested on your device, or because they have a few bugs (but are otherwise usable). This isn't always the case, but it can happen. If you've got your mind set on trying that app, Market Helper will let you "spoof" your device so the Play Store sees it as another phone, tablet, carrier or region. Just open it up, choose a device for which the app is compatible, and head back to the Play Store. You should find that app is available to download and install. Whether it works, of course, is another story.
When you're done, you can either reboot your phone or head back into Market Helper to restore your device to its original settings.
As always, be careful with apps like this. You may experience problems if you install something you aren't supposed to, so do so at your own risk. Be sure to check out the app's home page for information on permissions and other technical stuff.