There are a ton of these types of games but I think this is the original (I think) – connect the coloured dots with pipes but you cannot leave any empty squares and the pipes cannot overlap.
Over 2,000 free levels available in Free Play mode, and new Daily Puzzles every day!
10 different board sizes
Free Classic, Bonus, Bridges, Mania, Extreme, and Jumbo level packs
There are in-app purchases where you can buy hints and additional packs but there is more enough in the game to keep you going
Sounds basic, looks it as well but it is an extremely addictive game proving that sometimes the most basic ideas make the best games. Its a worthwhile addition to your games collection on your iPad
The video below sums it up