If you were unfortunate enough to buy this game your probably pissed that the game will take forever to complete. This may make some of the more obtainable achievements a bit easier.
Best solver I could find.
For the unsigned puzzles you can use this solver.
Just select board size and touch each cell you want to join then from the drop down menu select 'produces a result of' and enter the number. You will work it out after a clicking about for a minute.