Momentum

Inspiration

I’ve always loved time-lapse videos, they capture change in a way that feels almost magical. But making one is usually a hassle: storage issues, editing tools, figuring out stabilization. I wanted an app that makes documenting change effortless and automatic.

What it does

Momentum turns everyday progress into a movie you’ll never forget.

• Take one photo a day. It can be yourself, your plant, your pet, or your fitness journey.
• Momentum reminds you so you never miss a day.
• With a single tap, those photos transform into a polished montage you can instantly share.
• Each frame includes dates and notes so your story has context.

On the free plan, you can create and share montages easily. On the paid tier, you unlock pro tools like watermark-free exports and automatic face stabilization for perfect selfie time-lapses.

How I built it

Momentum is built with Kotlin and Jetpack Compose. The montage engine is powered by Android’s lower-level media APIs, which gave me faster and more configurable video generation compared to options like FFmpeg or third-party SDKs.

Challenges I ran into

The hardest part was video processing. I tested multiple approaches (FFmpeg, SDKs) before committing to raw Android APIs for speed and control. Balancing performance, reliability, and device compatibility was a challenge I had to dig deep to solve.

Accomplishments that I’m proud of

• Privacy-first: No data leaves the device. No unnecessary permissions. No hidden uploads.
• Effortless creation: A one-click montage workflow that hides all the complexity.
• Stable media engine: I built the core video system from scratch for flexibility and speed.

What I learned

Working directly with images and video frames gave me a real appreciation of how complex media pipelines are. I also learned the trade-offs between convenience (libraries like FFmpeg) and control (native APIs).

What’s next for Momentum

• Customization: Themes, transitions, and music tracks for montages.
• Streaks & gamification: Make daily photo-taking fun and rewarding.
• Community challenges: Inspire people to share and grow together.

Built With

• compose
• kotlin