Proto.io is a UI Design tool for Web. It costs about $288 a year, and a free tier is available. It rates 5 out of 5 across 2 reviews.
Features and pricing
| Usage | 2 |
|---|---|
| Review Average | 5 |
| Review Numbers | 2 |
| Platform | Web |
| Cost | 288 |
| Free | Yes |
| Offline | But prototypes can be viewed offline with native apps |
| Pen Tool | No pen tool |
| Collaboration | Simultaneous editing |
| Comments | Comments are supported |
| Handoff | Handoff not supported |
| Artboards | Multiple artboards can exist on a page |
| Symbols | No symbols |
| 3D Transform | Can't skew or edit perspective |
| Responsive | No responsive resizing |
| Prototyping | Native prototyping |
| Category | UI Design |