Remember how in Zack Snyder's 300 the action would speed up and then slow down and then speed up again and then slow down again?  

Depending on your tastes, that effect was really tiring or really cool, but either way, now you can attain a similar visual trick with Tempo, an iOS app that allows users to timelapse or slow down different parts of the same video clip.  

The app imports a video from your Camera Roll, and then you have to tap to find the portion of the video that you want to go slow-mo or to turbo charge. Tempo lets you adjust parts of video clips to four different speeds: Fastest (x8), Fast (x4), Slow (1/4x) and Slowest (1/8x).

The video will shift to the new pace automatically when you tap between the speeds, letting you combine both timelapse and slo-mo effects in the same video. These effects can be used to highlight a specific spot, create a dramatic moment or give fans of the Watchmen movie the tools they need to recreate that jail breakout sequence.

Tempo isn't a full editing suite however, so you won't be able to cut videos from beginning to end. However, if you missed a part, you can drag the video player back to any spot to change the speed. Tempo also gives you the option to import music from your own library to give your finished video a soundtrack.

Once the video is done, Tempo lets you share it across the usual popular social platforms like Instagram, Facebook, and YouTube.

Tempo was developed by Fly Labs, which also developed similar video-editing apps Clips, a simple video editing app, and Fly, a video editor that uses gestures. Download those and Tempo and you have a nice little portable editing suite in your pocket.

Tempo is also part of Facebook's recently released Messenger Platform. It is available for free with watermarking, or $4.99 for the premium version. Hopefully we will see an Android version shortly.