Jigsaw Puzzles Free is a fun puzzle game with one or two unusual extras.

The program has more than 3,500 picture to choose from, from a wide range of categories (landscapes, animals, film, TV, abstract and more). Choose one of three difficulty levels and the image is split into 9, 25 or 64 pieces. Solving the puzzle is as easy as dragging and dropping matching pieces next to each other, while a clock tracks your progress.

So far, so very normal, but what makes Jigsaw Puzzles Free different is that it's the front end for a web service. You can play it in your browser (if you have the Unity 3D plugin), or on a host of clients. Create a Binary Fortress account and you can submit pictures of your own. You gain "reputation points" for doing this, rating other people's images, adding comments to them, solving puzzles and more, and a "Top Members" chart shows how you're doing compared to other program users.

We had one or two problems while trying Jigsaw Puzzles Free. Individual pieces became noticeably darker when we dropped them into the correct place, for example, a problem when you're trying to match very similar colours. One puzzle stopped responding to our mouse, too, forcing us to reset it and start again.

Jigsaw Puzzles Free generally worked well, though. It has some ads, but they're not too intrusive. And if you need more, a paid-for Jigsaw Puzzles+ version includes an extra "Hard Difficulty Mode", can offer hints if you get stuck, and of course is entirely ad-free. It's yours for $1.99.