ArcSite allows you to Trim unwanted end parts of a segment, and Extend two segments together
Trim and Extend options are available as two different modes from the 2nd to bottom icon on the toolbar.
To change the mode, press and hold the icon. Tap the mode you want to use.
To trim, drag your finger or stylus across the object you want to trim. You can trim more than one object at a time
To extend, drag your finger or stylus across both objects you want to include in the extension operation.
While the video below shows an older version of trim and extend where they were available from the same mode, the actual trim and extend behaviors are still the same.