How can I squeeze video of certain length into smaller length
This is generally done by retiming the video. Usually, if you're retiming by anything other than double or half, you need to use a professional application such as Final Cut Pro X or Premiere. They will have options for doing the speeding up in a number of different ways such as "Frame Blending" or using "Optical Flow". 

For mobile, a quick search with these terms "app to speed up video iPhone" shows a number of results.