One of the ways you can show off your extreme geekishness is sporting a custom boot-sequence on your smartphone. Flashing a new boot animation isn't that hard (as long as you're rooted), but flashing it and rebooting has been the only way to preview the animation — and once it has been flashed onto your phone it's not much of a "preview" anymore.
The Boot Animation Previewer app wasn't built specifically with end-users in mind, rather, it was built for boot-animation artists to test out their creations before flashing them, but non-creators can use the app too — with no risk of boot-looping your phone in the process.
Give it a try and let us know what you think in the comments! If you've got an especially cool boot-animation, make sure you share a link with us, too!