Screencam is a freeware for Android that can be used to record activities on the screen of the phone and provide it in video format.
After screen recorded, and the video is to be trimmed to the exact video size or part needed, one would have to edit it.
The app comes with an edit option which provides a video trimming. But looking at the trimming, one cannot trim to a specific time limit, or even make the trim start from a particular time and end at another.
Thus I suggest the timing feature be added.
The video trimming option in the app looks like this
Here is a mock-up from another trimmer available
The feature can be implemented as shown below.
A start time, end time, and total time of the video could be added.
This option would give the users the ease and ability to make exact cuts in the video recording from their screen. They can cut or trim video to a specific time limit also, e.g 20minutes.