Plexus puzzles (series)

Plexus has created some of the most pretty and tough jigsaws I've ever played. It literally takes ages to even connect the first two pieces together due to the number of rotation steps and the misleading figures. But once you get the hang of it, it's really worthwhile. Recommended!

They have made some commercial jigsaws for iOS but I'll list the free ones here:

• Together till the end
• Circus puzzle
• Set the Stage
• Circus puzzle 2
• Always Room For More
• Heart in the Right Place
• Animal puzzle
• Rebuild the Earth
• Medieval Jigsaw
• A Peaceful Christmas
• You Complete Me
• Shiver me pieces
• Hollywood gone wild
• Fun To Boot
• Come Solve the Show
• FlutterBy
• Funny Farm
• Creepy Night Begins
• A Touching Masquerade