Fade in and Fade out
I believe that fade in and fade out effects is the most crucial and pretty common for all editing software, hope can find it in the next update
Jose Pina commented
You can already do this with the same transitions you would use for video. Just drag and drop a fade on the audio track.
Anissa Thompson commented
SOLUTION: If you are referring to AUDIO, then go to the AUDIO Panel (Ctrl+5), expand the Advanced section, and use AUTO-DUCK on the music/secondary audio track that you want to fade up/down while your main track is playing. If you are referring to VIDEO or AUDIO fade in or out, simply go to the EFFECTS Panel (Ctrl+2), and use the DISSOLVE option under the Transitions section. Dissolves can be applied to the end(s) of both audio and video clips.