First, if you have the App installed in your iPhone, please remove it. Second, on your computer, go to Control panel and select, 'Folder Options' Select, 'Do not show hidden files and folders' and remove the 'Hide extensions for known file types' Open iTunes and navigate to the applications folder. Locate your TomTom App. Back up this file before proceeding. Right Click the App and select 'Show in Windows Explorer' This will show you the file.IPA in windows explorer Next, you need to rename the file. At the end of the file, add '.zip' and hit enter. You will get this warning: Select 'Yes' You will notice the icon changed from the iTunes icon to a zip file. Double click the zip file and navigate to: Payload >US-Canada.app You will see this You will notice the North America folder and voices folder. The North America folder is where you place your custom POI files (.bmp & .ov2) The voices folder is where you will include your custom voices (.chk & .vif) INSTALL CUSTOM POIs Navigate to the 'North America' folder copy any custom POIs you have and paste it into this directory. It will take some time to copy over because of the compressing. Once your POI files are copied you will see them in the directory INSTALL CUSTOM VOICES Navigate to the 'voices' folder You will see the list of installed voices. You cannot add extra voices! You can only replace the existing voices with custom ones. Follow this list to know what voice each data file is: 00- Dansk Brigtte 01- Deutsch Werner 02 - Deutsch - Lisa 03 Missing 04- English(UK) - Tim 05-English(UK) - Jane 06- English(AUS) - Ken 07-English(US) - Lori 08- English(US) - Bonnie 09- English(US) - Richard 10- Espa?ol - Marta 11- Fran?ais - Jacques 12- Fran?ais - Catherine 13- Italiano - Chiara 14- Nederlands(NL) - Bram 15- Nederlands(NL) - Eva 16- English(US) - Mandy 17- Nederlands( - Lucie 18- Norsk - Liv 19- Svenska - Astrid 20- Norsk - Jorgen 21- Svenska - Patrik 22- Espa?ol - Antonio --------------------- 23- Dansk - Nils 24- Italiano - Roberto 25- Portugu?s - Joaquim 26- Portugu?s - Catarina 27- Suomi - Kati 28- Suomi - Matti 29- Nederlands( - Bernard 30- Greek - Olympia 31- Greek - Aristides 32- Ruskii - Anna 33-Ruskii - Vlad 34-Polski - Katarzyna 35-Polski - Andrzej 36-Eesti - J?ri 37-Slovencina - Barbara 38 is missing for some reason as well. 39-T?rk?e - Ozgur 40-Latviski - Ivars ------------------------------------------------ 41-Cestina - Miloslav 42- Malay - Erra 43- Bulgarian - Marius 44- Espa?ol(LA) - Norma 45- Espa?ol(LA) - Raul 46-Catalan - Maria 47- Srpski - Predrag 48- female - Shanghainese 49- Hrvatski(Croat) - Goran 50- Portugu?s(BRA) - Gabriela 51- Magyar(HUN) - Marika 52-Lietuvskai - Vladas 53- female - Cantonese 54- female - Mandarin 55- Japanese - Kiyoshi 56- Roman - Oana 57- Thai - Yue 58- female - Hakka 59- female - Mandarin(Taiwan) 60- female - Hoklo rename the custom file to the one you want to replace. I recommend you back up the file you are replacing. FINALIZATION Once you are done customizing, navigate back to the 'Mobile Applications' folder. Rename the APP file from the zip you created back to the original extension: '.ipa' by removing the '.zip' and hit enter. The icon will return back to the iTunes icon. Connect your iPhone to your computer, select your iPhone device and then scroll to the 'Applications' tab. Make sure the TomTom App is check or select the option I suggest before syncing to place your phone into flight mode. This will block any text or incoming call that can interrupt the long installation. To place your iPhone in flight mode: navigate to settings and select 'Airplane Mode' as ON. Then select 'Apply' on the bottom right to sync the App. Open your TomTom App to make sure it installed correctly. I only installed a custom POI so to check this I went to: Change Settings>Map>POI Types and the custom POI was listed: As of right now, you cannot add your favorites (MapSettings.cfg) without jailbreaking. The directory to add the favorites is created once it has been installed. It is not placed in the main 'US-Canada.app' directory.