With almost 400,000 to choose from, it can be notoriously difficult for one app to get noticed on the App Store. That’s why the success of Viddy, an app that we called ‘Instagram for Video‘ is so encouraging.

I’m not the only one to think so either, tech evangelist Robert Scoble, an early adopter of Viddy, tweeted about the app’s success yesterday.

Really interesting. #viddy app on iOS is getting 15,000 new users PER DAY with NO PRESS and NO MARKETING. Cool app, that’s why.

Viddy allows you to shoot short video clips, currently only 15 seconds long, and apply effects to them. These range from old-timey 8mm video to color shifting and even a 3D mode. The videos can then be shared in a feed that others can use to follow you and to comment on or favorite what you post.

The idea is a familiar one if you’ve used similar sharing apps for photos, but it’s a relatively new option for video sharing. There are a few other apps on the App Store that offer similar features like Social Cam and Tout, but Christina Wong of Viddy was quick to point out that none of them combines the in-app shooting, effects and social layer all into one app like Viddy.

In a conscious move, Viddy was ‘stealth launched’ on the App Store last monday. We discovered the app and ran our review without any press releases or notices being received from Viddy. There’s a simple reason that we didn’t get any press notices from Viddy. It didn’t send any out.

photo 2 Viddy getting 15k new users a day, with no advertising and little press

This move to just put the app out there on the app store and notify a few interest-makers rather than sending out a general release isn’t the norm. These days you have to make as much noise as possible just to have your app seen.

Now, about a week into it’s launch, Viddy is getting an average of 12-15k new users a day, largely on word of mouth of users and sites like TNW that thought the app was interesting to their readers and decided to post a review of it.

I spoke with Wong about Viddy’s strategy and it’s plans for the future and she shared some interesting tidbits with me.

The biggest request that I’ve seen from users on the app so far is for more effects, what Viddy calls Production Packs, and for the ability to add their own music from their library to their videos.

Wong says that they have more Production Packs on the way in phase 2 of the app, planned for a late summer 2011 release. Those packs will include new effects and music and some of them may be premium packs with a price attached. This would allow for in-app purchases to support Viddy.

photo 3 Viddy getting 15k new users a day, with no advertising and little press

Some of those Production Packs could also be branded, either with an event or perhaps with the personal brand of a movie or music star. Imagine for instance a ‘Thor’ pack promoting the upcoming Marvel movie that added thunder and lightning effects and perhaps gave your video a comic book style makeover. Couple that with snippets of the score for a full Thor-style video to share.

They currently don’t have any plans to support users pulling audio from their iTunes library because of copyright issues.

They’re listening to users about the maximum length of the videos as well. Currently they’re limited to 15 seconds but users are hungry for longer clips and Viddy wants to bring this in a future release as well.

In addition to these items, Viddy hopes to bring privacy settings, searching, groups, curated content as well as sharing on Tumblr WordPress and Foursquare in the phase 2 update.

Viddy is currently backed by $1.5 million in funding from investors including Battery Ventures, Bessemer Ventures, Qualcomm and some angel investors that include Jarl Mohn and early team members of YouTube. They obviously see the potential in a platform for video sharing that has the possibility of becoming the real ‘Instagram of video’.

It’s good to hear about a success like Viddy’s in the ever more crowded app space. Like many Viddy users, I’ll be waiting for phase 2 to see what this app can really do.

You can email any suggestions you have for the folks at Viddy to info@viddy.com and you can download the app on the App Store here for free.