Here are some ideas for apps that I would pay for, but haven't found either on Mac or iOS. These might be an interesting project to work on, since you can commercialize them for $4.99 - $99. Below I'll list things that I want to buy and a price range that would be the minimum starting point that I'm excited to pay.
Video Water Mark Software for Mac 10.10+ ($19.99 - $99.99)
- Modern video watermark software to process 100+ videos at a time using batch exporting
- Add image watermark (resize/position/transparency)
- Add text watermark (resize/position/transparency)
- Must use AVFoundation (GPU/CPU accelerated)
- Needs batch rendering support (Drag and drop list with add/remove/filepath destination)
- UI needs to be responsive, do loading in background and update main thread.
- Support at least .mp4 and .mov file format (more for other users)
- Similar to VideoMark, iLove Video Watermark, or Watermark Video (read reviews or download for flaws)