The WhatsApp messenging system, which allows users to send messages for free, has topped Apple\'s App Store Official UK charts. WhatsApp Messenger held off Pandemic 2.5 - a game in which players aim to spread a disease across the world - leaving it in second place. The leading app, from WhatsApp Inc, allows cross-platform mobile messaging that lets people exchange messages without having to pay for SMS. Third place on the iPhone paid-for charts went to Angry Birds Space by Rovio Mobile Ltd, a puzzle game based on the successful Angry Birds game series. Meanwhile, top of the free iPhone charts was BSkyB\'s Sky Sports News app which allows sports fans to keep up-to-date with the world of sport. SayHi Translate by SayHi - an app that translates what you dictate - was top of the paid iPad apps chart, and motorbike racing game Highway Rider by Battery Acid Games took top spot of the free iPad chart. The App Store Official UK Charts - Week 19 iPhone (Paid): 1. WhatsApp Messenger - WhatsApp Inc. 2. Pandemic 2.5 - Dark Realm Studios. 3. Angry Birds Space - Rovio Mobile Ltd. 4. SayHi Translate: Use Your Voice To Speak A New Language Like A Pro - SayHi. 5. Cut The Rope - Chillingo Ltd. 6. Draw Something by OMGPOP - OMGPOP. 7. Free Music Download Pro - Downloader and Player - BSOSoft. 8. Hospital Frenzy - Tanya Barnes. 9. Ronnie O\'Sullivan\'s Snooker - P1 Sports Ltd. 10. GPS Navigation 2 - SatNav by skobbler (UK/ROI) - skobbler GmbH. iPhone (Free): 1. Sky Sports News for iPhone - BSkyB. 2. 100 Floors - Tobi Apps Limited. 3. Logos Quiz Game - AticoD. 4. Highway Rider - Battery Acid Games. 5. Penalty Soccer 2012 - Bakumens. 6. Rope \'n\' Fly 3 - From Dusk Till Dawn - Robert Szeleney. 7. Pocket Whip - App City. 8. Puzzler Wordsearch - Puzzler Media Ltd. 9. Socialcam Video Camera - Justin.tv 10. Instagram - Burbn, Inc. iPad (Paid): 1. SayHi Translate: Use Your Voice To Speak A New Language Like A Pro - SayHi. 2. LEGO Harry Potter: Years 5-7 - Warner Bros. 3. Art Set - LOFOPI. 4. Batman Arkham City Lockdown - Warner Bros. 5. Robbery Bob - Chillingo Ltd. 6. Pages - Apple. 7. Ski Safari - Defiant Development. Shark Dash - Gameloft. 8. Angry Birds Space HD - Rovio Mobile Ltd. 9. LEGO Harry Potter: Years 1-4 - Warner Bros. 10. iPhoto - Apple. iPad (Free): 1. Highway Rider - Battery Acid Games. 2. Rope \'n\' Fly 3 - From Dusk Till Dawn - Robert Szeleney. Skill Game - Good Apps UG. 3. Logos Quiz Game - AticoD. 4. Penalty Soccer 2012 - Bakumens. 5. MyBowling 3D - iWare Designs Ltd. 6. eBay for iPad - eBay inc. 7. Skype for iPad - Skype Software S.a.r.l 8. BBC iPlayer - Media Applications Technologies Ltd. 9. Hidden Objects - Tobi Apps Limited. 10. LinkedIn - LinkedIn Corporation.