I’m no actor, but as the child of one -- and now subject to running lines with my actor/improviser boyfriend -- I feel I’m qualified to tell you that the free Rehearsal iPhone app is a must-have app for anyone working or trying to break into television, film, theater or voice-over work. Designed by working actor  David H. Lawrence XVII (he’s kidding, calm down), who you might know as Eric Doyle on NBC’s "Heroes", or as the taxi driver in that really boring Kate-centric episode of "Lost" this season, Rehearsal is designed to help actors and other production personnel organize scripts for auditions and working on set. It may also save your relationship when your significant other just can’t bear to run a scene with you again.

After importing a script, users will be able to highlight lines in four colors. After highlighting, you can easily black out the lines by tapping the black “B.” Touching the lines will make them reappear so you can flick back and forth while memorizing. Each script has a built-in recorder to record a table read or practice session, which means you don’t have to recruit a line-reading partner. Double-tapping the screen gives you the option of adding text, video or photo comments to your script margins. Users can also add beat notations to break up lengthy monologues.

In "My Scenes," there’s something extra for voice-over talent. If you audition via email, you can use Rehearsal to record your scene to perfection. Once you’ve got it right, you’ll be able to email the file as an MP3 directly from the iPhone app.

Rehearsal is a free download and gives users a free week of unlimited script uploads. After that, users will be need to pay $1.99 per script, $19.99 per month for unlimited importing or $199.99 per year for unlimited scripts. Until the end of March, Sotto Voice Filmworks has cut prices in half to 99 cents, $9.99 and $99.99, respectively, so don’t wait too long. It’s not cheap, but it could help you land that part.