I just bought your app and funny thing is after convert it actually increased the size rather than slimed it what happen?
The videos created by cameras on iPhone, iPad or iPod touch are of high quality and resolution natively, and, as such, take up huge amounts of space on your iOS device. If you want to shrink the iOS video files to free up hard drive space on iPhone, you can try the Video Slimmer App.
This video compressor makes use of compression codecs, video bitrate drops, dimension reduce, screen resolution drops to reduce file size of your iPhone/iPad/iPod captured videos. After converting, you should get much smaller file size with quite reasonable video quality for playback on your iOS device or other mobile devices and players.
Sometimes with specific video sources, most likely not those native iOS recorded videos, you may find after converting, the actual video file size gets increased rather than slimed.
The issue might happen when:
1. You are trying to slim a compact video which is already very small in file size considering its dimensions or length.
2. You have enlarged the video resolutions or dimensions. Some videos are with lower resolution than others and if you try to compress a lower resolution video into a higher resolution format, the video file size may actually increased other than slimed down. For example the source videos is 720p, however you tried to convert it to 1080p. See How to Trim iPhone video size?
3. You have set better video quality with higher bit rate, thus the file size grows and that's why you get larger file size after converting.
You can choose resolutions or reduce video quality slightly from the Settings panel, see How to Change Output Video Profile and Settings?